FTTH connection proper MTU Size and Jumbo frames

I've recently moved to a ISP that provides a 4mbps connection through FTTH(Single OFC). There is a EPON ONU in my premise from which a RJ-45 lan cable is connected to my Intel DH67CL1 board based PC. manual says, the NIC is a gigabit ethernet card. I tried setting MTU of 8996 and I can ping and browse fine. But, I'm totally in dark whether this value is optimum and works flawlessly browsing sites. How to find and set the proper MTU for a fibre network like this? Is the value correct?
I tried like this decreasing mtu value:
ifconfig eth0 mtu 8997
SIOCSIFMTU: Invalid argument
then,
ifconfig eth0 mtu 8996
^^^ No error message and it seems accepting.
BTW, from arch wiki, I saw that the driver module(e1000e which is used here) used by NIC have some bug report filed wr.to Jumbo frame. Am I doing things correctly? Earlier MTU was at default 1500. Please guide. thank you
Some drivers will prevent lower C-states
Some kernel drivers, like e1000e will prevent the CPU from entering C-states under C3 with non-standard MTU sizes by design. See bugzilla #77361 for comments by the developers.
https://wiki.archlinux.org/index.php/Ju … mbo_frames

yeah, i actually talked to support and they told me the same thing. just another example of misleading information from Linksys as here is what the manual and the help page say:
MTU
MTU is the Maximum Transmission Unit. It specifics the largest packet size permitted for Internet transmission. Select Manual if you want to manually enter the largest packet size that will be transmitted. The recommended size, entered in the Size field, is 1500. You should leave this value in the 1200 to 1500 range. To have the Router select the best MTU for your Internet connection, keep the default setting, Auto.
no where in that description does it say that 1500 is the maxmium.
because this is also a gigabit switch, one would expect that jumbo frame support is not out of the realm of possibility. as a point of reference any other $50 (or less) gigabit switch supports this, but that's what i get for expecting too much from Linksys.
thanks for the info.

Similar Messages

SRW2048 and Jumbo frames

I have a Cisco SRW2048 (Firmware 1.2.2d, boot 1.0.0.05) on which I have enabled jumbo frames but yet when I attempt with a Windows 2003 server to ping the mgmt IP of this switch with a frame over 1472 (ping -f -l 1472 w.x.y.z) I get a response of "Packet needs to be fragmented". The server is connected to a Netgear gig switch (GS724AT) that has jumbo frames enabled and working as I can talk to other devices using jumbo frames. Attempts to access the SRW2048 switch fail on packets larger than 1472. I have also attempted a Windows 7 box using jumbo frames to no success. The Windows 7 box works when connected to the Netgear switch but when I move the connection back to the SRW2048, jumbo frames on the windows box stop working.
Any help or suggestions would be appreciated.
Thanks.
David

On the SF-300 and SG-300 for Jumbo to work the Enable Jumbo checkbox must be unchecked. Either I don't understand Cisco logic or it's a bug in the GUI.

Wrt600n mtu above 1500 / jumbo frames?

hi, i've been playing around with my environment to try and increase speeds and have started to modify and test jumbo frames / MTU. according to the WRT600N manual, the recommended mtu size is between 1200-1500, but can be changed when changing from auto to manual.
only one problem with that, when i switch it to manual, and try and do anyting above 1500 a dialogue box pops up and says "the mtu size must be bewteen 576 and 1500". i did a quick search on the forum, and didn't see anything related to this.
has anyone else ever tried to talk to support and see if this is something that can be increased?
Message Edited by d-rick on 04-19-2009 09:36 AM

yeah, i actually talked to support and they told me the same thing. just another example of misleading information from Linksys as here is what the manual and the help page say:
MTU
MTU is the Maximum Transmission Unit. It specifics the largest packet size permitted for Internet transmission. Select Manual if you want to manually enter the largest packet size that will be transmitted. The recommended size, entered in the Size field, is 1500. You should leave this value in the 1200 to 1500 range. To have the Router select the best MTU for your Internet connection, keep the default setting, Auto.
no where in that description does it say that 1500 is the maxmium.
because this is also a gigabit switch, one would expect that jumbo frame support is not out of the realm of possibility. as a point of reference any other $50 (or less) gigabit switch supports this, but that's what i get for expecting too much from Linksys.
thanks for the info.

Dual nic NAS and Jumbo Frame

I am posting this on the server area because I doubt I am going to get an answer anywhere else.
I have a linux based NAS running netatalk and avahi (afp server and bonjour) with two nics and I have a brand new Mac Pro with two NICS. What I want to do is run a crossover cable between the NAS and the Mac Pro in addition to both being plugged into the normal network. The normal network would have 1500 byte mtu so my internet performance and all of the various vintages of print servers work ok. The dedicated network would have jumbo frames. As we get more Mac Pros, we would add a switch and more machines to this secondary jumbo frame network.
That in theory should work fine (I have done it with other operating systems). My quandary is how to get the Mac to always connect to the NAS via the Jumbo nic and not through the other nic? The Mac learns of the server via Bonjour, so how do I tell it to prefer the "appearance" of the server on the jumbo NIC vs the appearance on the normal network. I know with WINS or DNS I can override the name resolution with a LMHOSTS or hosts file entry, can I do the same with Bonjour?
Thanks for any help or any pointers in the right direction!

I think you are misguided in your assumption that I am not intimately familiar with TCP and don't know what I am talking about.
TCP does not "negotiate" MSS, it advertises the MSS of each side to the remote in the 3 way handshake. It is perfectly acceptable to have asymetric MSS values. TCP does NOT NEGOTIATE a common MSS size. On a LAN, this will result in a functional communication. UDP however does not have such mechanisms and will fail.
TCP will also not function properly in the scnario of my local workstaion with jumbos enabled communicating with a distant endpoint that also has jumbos enabled across a transit network that does not support the maximum MSS used by one of the end stations. For giggles let's say the far end is FDDI and has 4k frame size. Our transit does not support frame sizes larger than the "natural" frame size of 576 bytes. We will use a 4k frame size from me to the remote and a 9k from the remote to me. If the remote sends to me it can use the full 4k MSS of token ring because its less than my MSS. In the reverse my workstation would send 4k frames back to the token ring station. Successful communication would then depend on path MTU and intermediary routers to send ICMP type 3 code 4 messages to signal back to our end stations to reduce our MSS (assuming the DF bit is set on our traffic or the transit router is incapable of fragmentation).
This is perhaps a bit of a flippant example in that nobody would be running FDDI or Token ring anymore, but random entities on the internet will run jumbo frame and perhaps some other l2 technology we aren't familiar with.
Did you ever deal with someone on a token ring segment trying to hit 3Com's web site when it was fddi or token ring? I have on several occasions. I also see this with VPNs all the time. Cisco's genius recomendation is to reduce your MSS on your server as some of their products don't support PMTU. I have had a Cisco <-> Juniper VPN where transfers worked one way because the Juniper would silently strip the DF bit from the packet and fragment it and the Cisco router (38xx) wouldn't do the same in the reverse direction. I also went through **** with the Nortel Contivity VPN devices while they sorted out what to do with the whole MTU negotiation issue.
I have spent many hours of my life pouring through sniffer captures because of mismatched MTUs. Let's not forget the old days of FDDI backbones with ethernet segments bridged across them and FDDI attached servers... mismatched buffers... no thanks.
I therefore don't want to waste my time troubleshooting some bizzare networking issue when there is a perfectly valid way of solving the issue for absolutely minimal expense. I am moving large files here (certainly large enough to get well out of TCP slow start), we easily saturate the full gig link minutes at a time and a saturated gigabit link at standard frame size is inefficient due to the interpacket gap which is locked at 96 bit times for ethernet and the 40 bytes of TCP/IP header plus whatever application payload is prepended per packet on each link. Cutting the number of TCP/IP headers and (probably more importantly since most decent nics do checksum offload these days) application layer headers also reduces load on both client and server.
On large sequential bulk data transfers jumbo frame effectively increases performance and reduces overhead. Period. I have implemented it from the early days of Alteon hardware in Sun servers through Juniper EX products last week. Every iSCSI implementation I run into is jumbo frame based for those exact reasons.
That being said, I don't need to restrict anything. All I want to do is to override bonjour/mDNS for this particular host such that the Pro always communicates over the jumbo segment. This is easily accomplished in windows with an LMHOST entry or in a unix environment with a HOSTS file entry. Is there some way to override bonjour from the client side? I'm ok even statically defining the services presented by bonjour on this host.
I am also willing to force all bonjour requests through a DNS server, however Apple doesn't have any decent documentation on how this is accomplished in an enterprise environment.

Catalyst 3750 and jumbo frames

We're looking to implement a gigabit segment with a 3750 switch, with the latest apple imac G5 clients connected and and an xserve G5 connected doing link aggregation using a 4 port smalltree NIC.
Although the Xserve supports jumbo frames i believe the imac NICs DON'T support jumbo frames although the operating system does( the imac NICs DO support 1000T ) Ideally we'd want the 3750 switch to be configured for Jumbo frames. The 3750 switch we've chosen has all ports of 10/100/1000T with the SMI, so all ports will have the MTU set at 9000 if we enable jumbo.
Although the Xserve will be fine, i'm worried about traffic that ingresses from the xserve and egresses out to a 10/100/1000 port to which an imac is connected which i believe does not support Jumbo frames. What are the issues in terms of connectivity and dropped packets for an imac G5 connected to a 3750 ?
seeing as the MTU is set globally and all our ports are gigabit, and machines will be connected to these ports that don't support jumbo but are advertised as having 'gigabit capability'
Sorry if these sounds like an incoherent rant, but i needed to provide as much info as possible. Help much appreciated

just to add, in comparison HP gigabit switches can do jumbo vlan on a per vlan and per port basis it's a shame the 3750 can't do that

Linksys SE2800 and jumbo frames

Does the Linksys SE2800 gigabit 8 port switch support jumbo frames? Anyone have this switch? Any issues? Looking to replace a netgear gigabit switch that likes to forget that it has gigabit machines connected to it.

Hi Michael,
Actually had a chat with a colleague at linksys regarding your question, but he referred me to a datasheet, which left me with the question I started with. The technician said yes it suppported Jumbo frames but he could post me nothing in black and white..
Why not look at the Cisco Small Business umnanaged product the SG100D-08. It offers as the datasheet suggets;
Peace of mind:
All Cisco 100 Series switches are protected for the life of the product by the Cisco Limited Lifetime Hardware Warranty
Also, even though an unmanaged product, this series supports such features as;
1. Green Energy—Efficient Technology
The Cisco SG 100D-08 switch supports Green Energy-efficient
Technology. It can enter sleep mode, turn off unused ports, and adjust
power as needed. This increases energy efficiency to help businesses use
less power and save money.
2. Jumbo Frame Support
The Cisco SG 100D-08 switch supports frames up to 9,000 bytes called
jumbo frames. Jumbo Frame support improves network throughput and
reduces CPU utilization during large file transfers, such as multimedia files,
by allowing larger payloads in each packet.
regards Dave

Question about image size, canvas size and Picture frame

Hi,
This has always been a little confusing so let me describe what my question is:
Assume I have a created a new PSD that is 8 1/2 x 11.
The canvas size is the same 8 1/2 x 11.
I want to put a border around the picture (say 1/2 of an inch all around), and put the finished picture in a Picture frame. After it is in the frame, you would be able to see the entire picture plus the border.
Q. Should I change (reduce image size) of the PSD to (for this example), 8 x 10 1/2. Then increase the canvas size to 8 1/2 x 11. After I increased the canvas size, do a Paint Bucket fill with white (to create the White border)? then print the changed size PSD on 8 1/2 x 11 paper so that it will fit into a 8 1/2 x 11 picture frame
I realize I could have just created the new PSD to be 8 x 10 1/2 in the first place.
Hope I made this somewhat clear.
Bob

1: Decrease the size as you describe.
2. Go to File>New or Ctrl N
3. Make the box 8.5x11. Make sure the other data conforms to your image.
4. Now,holding down Ctrl-Shift, Drag the image to the new box and release the mouse. Your image will be centered in the box.
Note: there may be a method to do this including any adjustment layers, but I usually only do this as a last step, flattening a copy of the working file.

TCP Segmentation Offload and Jumbo Frames.

I have VmWare-OpenSolaris and VMXNET3 network card.
Can i enable subj?
#:> ifconfig vmxnet3s mtu 5000
ifconfig: setifmtu: SIOCSLIFMTU: vmxnet3s0: Invalid argument

Hi sdavids5670
Did you ever find a proper fix to your issue? was updating the N1Kv a solution?
I have exactly the same symptoms with a N1Kv [4.2(1)SV2(1.1a)], F5 (ASM), vmxnet3 guests, however I'm failing all RDP (win2k8r2) and SSH large packets (redhat); the rest of my traffic appears fine. This only occurs when the F5 resides on the same VEM or VMware host as you have seen. My packet captures are similar.
My work around is two fold. Firstly create rules to isolate the F5 onto hosts where guests are not utilising it and secondly, disable TCP offloading (I use IPv4 only). Neither of these are solutions.
I have not tried a non-F5 trunk (ie, perhaps a CSR1000v) to replicate this without the F5.
I suspected that the onbox / offbox issue was something specific about the logic of the VEM installed on the host (that's how I justified it to myself) rather than VEM->VEM traffic. It appears that only vEth -> vEth traffic on the same VEM is the issue. Also, I can only replicate this when one of the vEth ports is a trunk. I have yet to be able to replicate this if both are access port-groups (vEths).
I have yet to log a TAC as I wanted to perform testing to exclude the F5.
Thought that I would just ask....
Cheers
David

T61 and Intel 82566mm Jumbo Frame Capable?

I'm trying to achieve the near 100MB/sec performance with my NAS but cannot seem to get past 15MB/sec with 25MB/sec bursts on my gigabit LAN. Do I need to enable jumbo frames for this to work? If so, is the Intel 82566 gigabit NIC even capable of jumbo frames or is this an OS dependent issue? In addition, does my switch also need to have jumbo frame support or is it built into gigabit? And lastly, how would this adversely affect my 802.11n clients connecting to my server - are jumbo frames something 802.11n clients capable of?
T61_Wide | Model No. 7662 - CTO
Core 2 Duo T7250 | 2GB OCZ DDR2-800
82566MM Gigabit | 4965AGN Centrino Pro

check BIOS / configuration and see if INTERNAL LAN is enbaled or disabled. i had this happen when my wireless and lan were not working. fixed it in bios.
T7600, T60p - 2GB - 2.33GHZ - 100GB

What do the "Automatic" settings do for Frame size and Frame rate in Compressor 4.1.1?

Can anyone tell me, very specifically and with technical detail, what the "Automatic" settings do (in Compressor 4.1.1) for the following setting attributes: (1) Frame size and (2) Frame rate
Thank you!

Hi, in addition to Russ's advice for the VIDEO PROPERTIES in the Inspector, you might consider the "automatic" options being proposed by compressor.app V4.1.x as OPTIMAL for the destination codec you have specified that deviate (or differ in some way) form the MASTER (source) from where your are transcoding. There's no real TECHNICAL detail. These UI values simply are passed as parameters to the codec. The image/audio results can be PREVIEWed ofcourse in the compressor.app V4.1.x UI (Current PAne) ... us the slider and the timeline to determine final taste!
Suggested Examples may include:
REDUCED frame rate for a slower device or stream or bit rate or destination dleivery platform
reduced bit rate for older devices
smaller FRAME SIZE for say SD devices specified
INCREASED frame size with added "padding" in a situation like LETTERBOXING (4:3 in a 17:9 for example.. may others)
ye old PAL to NTSC conversion
inter-frame group of pictures (GOP) for distribution.
Scaling
retiming
cropping verses scaling
or simply what compressor.app "thinks" would work best - usually the best for most work.
others will have many more suggestions.
Also note that there are some nice overidding settings in the inspector/Video for resizing and retiming and Cropping you might consider.
For client based production distributions, many of us use CUSTOMISED settings. You may create and delete these on an AS NEEDED basis.
Lastly, There's likely a good write up the defaults in the latest Compressor.app V4.1 Users Guide PDf - you might want to pull it down from http://manuals.apple.com and shove it in ibooks.app. I recommend getting a copy. Also get the latest FCPX 10.1 Users Guide and Motion while you're there. Great for iPAD and iPHONE too if you get bored.
FWIW.
Warwick
Hong Kong

Airport Extreme with Gigabit Ethernet - Does it have jumbo frame support?

Please, can I get definite answer to this question? I do not need speculations as I read some reviews already. Can we have Apple finally put complete specification of the product rather than "popular one" with attachement of protocol numbers?
I just need simple answer possibly from Apple engineering team to the following questions:
1. Does current Airport Extreme have support for jumbo frames (everything above 1500bytes per frame)? (if one does not know what that is them perhaps understanding acronym "MTU" can help a bit)
2. If there is support then what is the maximum supported size of jumbo frame? (Some products do not go above 6k and I read some statistics that traffic somwhere is usually 66% at about 4k jumbo frames and above that there is not much...)
3. If there is no support then does Apple plan on update for this (firmware or hardware) in the future?
Please, do not tell me that someoene ran something with jumbo frame and it worked as I tried yesterday LaCie Ethernet drive with supposedly setup (I set it myself) of jumbo frame 4k and on soft reboot of the drive it worked when connected to Airp[ort Extreme, but after hard reboot the disk is not visible anymore. I will recover the disk, but I need to understand if I have chance of using jumbo frames that tremendously improve performance with large files (e.g. try movies stored for AppleTV on network drive) when using Airport Extreme with its gigabit Ethernet... or that is just Gigabit Ethernet for product marketing purposes only.
I just need reliable answer by product specification that should be on paper at Apple, but it is not so I hope that one of guys here has access to some engineering team.
Thank you,
Maciek Samsel

The spec. on the chip used by Apple support your conclusion.
BCM5395 Features
Complies with IEEE802.3, IEEE802.3u, IEEE802.3ab standards
5 10/100/1000Mbps Auto-Sense RJ45 ports supporting Auto-MDI/MDIX
All ports Support Full/Half Duplex transfer mode for 10/100Mbps and Full Duplex transfer mode for 1000Mbps
Port-based and MAC-based VLAN
IEEE 802.1Q-based VLAN with 4K entries
Port-based rate control
Port mirroring
Compact field processor (CFP)
512 rules
Filtering, classifications, remarking, and priority actions.
Priority modification on egress
DOS Attack Prevention
Loop detection for unmanaged configurations with Broadcom’s patented LoopDTech™ technology
CableChecker™ with unmanaged mode support
Double tagging
IEEE 802.3x programmable per-port flow control and back pressure, with IEEE 802.1x support for secure user authentication
4K entry MAC address table with automatic learning and aging
128-KB packet buffer
128 multicast group support
Jumbo Frame support up to 9728 byte

Enable Jumbo Frame Support On UCS

Could someone direct me to the documentation for the proper way to enable jumbo frame support on UCS? I'm trying to troubleshoot a problem and have configured MTU of 9000 from ESX running on a blade to an NFS server off a Nexus 5k. I have good documentation for configuring jumbo frame support on the Nexus 5k and on ESX but nothing really specific for UCS.
For Nexus 5k:
http://www.cisco.com/en/US/docs/switches/datacenter/nexus5000/sw/configuration/nxos/Cisco_Nexus_5000_Series_NX-OS_Software_Configuration_Guide_chapter33.html#con_1150612
show run:
policy-map type network-qos jumbo
class type network-qos class-default
mtu 9216
system qos
service-policy type network-qos jumbo
For ESXi:
esxcfg-vswitch -m 9000 vSwitch0
esxcfg-vswitch -A IP_Storage vSwitch0
esxcfg-vswitch -v 31 -p IP_Storage vSwitch0
esxcfg-vmknic -a -i 10.254.31.2 -n 255.255.255.192 -m 9000 "IP_Storage"
Testing:
I have been able to ping (with large payload) the NFS host interface from a temporary vlan interface on the N5k. I cannot do the same to the ESX hosts or between hosts.
Thanks,
-R

Russell
What network adapter are you using? M81KR or the M71KR's or any other?
The MTU is set on a per CoS basis in UCS. If you do not have any QoS policy defined for the vNIC that is going to the vSwitch, then the traffic is going to Best-Effort Class. All you need to do to enable jumbo frames is to enter the MTU to be 9000 in the MTU pulldown for whatever class the traffic is going to.
Its also given in the user guide -
http://www.cisco.com/en/US/docs/unified_computing/ucs/sw/gui/config/guide/1.3.1/UCSM_GUI_Configuration_Guide_1_3_1_chapter18.html
MTU drop-down list
The maximum transmission unit for the channel. This can be:
An integer between 1500 and 9216. This value corresponds to the maximum packet size.
fc—A predefined packet size of 2240.
normal—A predefined packet size of 1500.
Note
This field is always set to fc for Fibre Channel.
--Manish

Jumbo Frame support

Hi all
I have a vendor that wants to run an application called mirrorview to do a bandwidth test for a new application; the only requirement is that I support jumbo frames on my uplinks. I do not currently have my ports configured to support jumbo frames, are there any benefits or drawbacks to supporting jumbo frames? If so please post so I can weigh those options before I reconfigure my uplinks.
TIA Rodney.
FYI I am running 6500 hybrid in the core , and 3550-xx at the edge.

If jumbo frames are enabled only on uplinks but not all the way between two systems, then the end systems won't take any advantage of jumbo frames. There is no drawbacks of jumbo frames as such as far as I know, but some pitfalls.
Jumbo frames are any frames bigger than standard Ethernet frames (1518 bytes of user-visible part). And some platforms implement jambo frames as big as 9216 bytes (Cat 6500), while others (e.g. Cat 2950) are limited to baby-jumbo of 1530 bytes. So when you enable jumbo frames you must be sure that the size of jumbo frame is consistent across all your systems including servers and client PC's connected to your network.
Another pitfall is that if you enable jumbo frame on any IP-layer interface this will automatically change IP MTU. If you're running OSPF and jumbo frames are enabled only on some systems connected to a subnet but not on other systems from the same subnet OSPF adjacencies will not form until you specify 'ip mtu 1500' on jumbo-enabled systems. As soon as you do this, effect of jumbo frames for IP traffic will be void (but it might still be necessary for things like MPLS). So be sure that systems on common subnet have same MTU.
Routing problem is easy to detect, more general problem is that travelling across L2-only path there is no way for switches to send 'ICMP Fragmentation required' if packet is large then next interface MTU. This will break PMTU Discovery and since most applications usually sent packets at max MTU and DF-bit set, there will be timeouts. So again, consistent MTU across whole L2 path is important.
By the way, if your servers and PC's are not connected via jumbo-enabled links then you unlikely see any difference by enabling jumbo frames on the uplinks because both 6500 and 3550 catalysts are capable of wirespeed performance. The only time when it makes sense to enable jumbo frames only on the core links is when you need some non-IP headers to encapsulate your max-sized IP packets (MPLS is one such example).
As for benefits - servers running (very) heavy traffic applications (think full-feed USENET server with multiple fast peerings) may benefit from sending large portion of data in each packet, so for the same amount of data they need less number of packets. Destination system will have to handle less interrupts and overall performance may increase.
Hope this helps.

How do I maximize LAN speeds using Gigabit Ethernet, jumbo frames?

I move a lot of large files (RAW photos, music and video) around my internal network, and I'm trying to squeeze out the fastest transfer speeds possible. My question has to do both with decisions about hardware and what settings to use once it's all hooked up.
This is what I have so far:
-- imac 3.06GHz, macbook pro 2.53GHz
-- Cisco gigabit smart switch capable of jumbo frames
-- Buffalo Terastation Duo NAS (network attached storage), also capable of Gbit and jumbo frames
-- All wired up with either cat6 or cat53e.
-- The sizes of the files I'm moving would include large #s of files at either 15MB (photos), 7MB (music), 1-2GB (video) and 650MB (also video).
-- jumbo frames have been enabled in the settings of the macs, the switch and the buffalo HD.
-- I've played with various settings of simultaneous connections (more of a help with smaller files), no real difference
-- Network utility shows the ethernet set to Gbit, with no errors or collisions.
-- have tried both ftp and the finder's drap and drop
-- also, whenever I'm doing a major move of data, I kick my family off the network, so there is no other traffic that should be interfering.
Even with all that, I'm still lucky to get transfer speeds at 15-20mbps, but more commonly at around 10. The other odd thing I've encountered while trying to up my speeds, is that I might start out a transfer at maybe 60mbps, it will maintain that for about 30-60sec and then it appears to ramp itself down, sometimes to as low as 1-5mbps. I'm starting to think my network is mocking me
I also have a dual band (2.4/5) wireless n router (not jumbo frame capable), but I'm assuming wired is going to trump wireless? (NOTE: in my tests, I have disabled wireless to force the connection through the ethernet).
Can anyone help with suggestions, and/or suggest a strong networking reference book with emphasis on mac? I'm willing to invest in additional equipment within reason.
Thanks in advance!
juliana

I'm going to pick and choose to answer just a few of the items you have listed. Hopefully others will address other items.
• This setup was getting me speeds as high as 10-15MB/sec, and as low as 5-6MB/sec when I was transferring video files around 1-2 GB in size
I would think a single large file would get the best sustained transfer rates, as you have less create new file overhead on the destination device. It is disturbing that the large files transfer at a slower rate.
• Would a RAID0 config get me faster write speeds than RAID1? I have another NAS that can do other RAID configs, which is fastest as far as write times?
RAID0 (Striped) is generally faster, as the I/O is spread across 2 disks.
RAID1 is mirrored, so you can not free the buffer until the same data is on BOTH disks. The disks are NOT going to be in rotational sync, so at least one of the disks will have to wait longer for the write sectors to move under the write heads.
But RAID1 gives you redundency. RAID0 has not redundency. And you can NOT switch back and forth between the 2 without reformatting your disks, so if you choose RAID0, you do not get redundency unless you provide your own via a backup device for your NAS.
• what is the most efficient transfer protocol? ftp? smb? something else? And am I better off invoking the protocol from the terminal, or is the overhead of an app-based client negligible?
Test the different transfers using a large file (100's of MB or a GB sized file would be good as a test file).
I've had good file transfers with AFP file sharing, but not knowing anything about your NAS, I do not know if it supports AFP, and if it does, whether it is a good implementation.
If your NAS supports ssh, then I would try scp instead of ftp. scp is like using cp only it works over the network.
If your NAS support rsync, that would be even better, as it has the ability to just copy files that are either NOT on the destination or update files which have changed, but leave the matching files alone.
This would help in situations where you cannot copy everything all at once.
But no matter what you choose, you should measure your performance so you choose something that is good enough.
• If a client is fine, does anyone have a suggestion as to best one for speed? Doesn't have to be free -- I don't mind supporting good software.
Again just test what you have.
• Whats a good number to allow for simultaneous connections, given the number of files and their size?
If the bottleneck is the NAS, then adding more I/O that will force the disk heads to move away from the current file being written will just slow things down.
But try 2 connections and measure your performance. If it gets better, then maybe the NAS is not the bottleneck.
• What question am I not asking?
You should try using another system as a test destination device in the network setup to see if it gets better, worse, or the same throughput as the NAS. You need to see about changing things in your setup to isolate where the problem might be.
Also do not rule out bad ethernet cables, so switch them out as well. For example, there was a time I tried to use Gigabit ethernet, but could only get 100BaseT. I even purchased a new gigabit switch, thinking the 1st was just not up to the task. It turned out I had a cheap ethernet cable that only had 4 wires instead of 8 and was not capable of gigabit speeds. An ethernet cable that has a broken wire or connector could exhibit similar performance issues.
So change anything and everything in your setup, one item at a time and use the same test so you have a pear to pear comparision.

MTU Size Problem Loading Certain Webpages

Hello Colleagues,
I'm having a strange problem dealing with MTU sizes and loading certain webpages. I am aware of the default Microsoft MTU of 1500 and also using GRE IPSEC Tunnels recommended at MTU size 1400. I have since manually set some users PC's to MTU of 1400 and most of those users are experiencing no issues. However, there are a few users who still experience website loading issues even though I have manually changed their MTU size to 1400.
These are domain accounts will the same image loads on their machines, so all have the same permissions, rights, firewall settings, etc. They all use the same LAN, switches, and routers.
Here are the router configs, router 1 and router 2
Router 1
Current configuration : 9006 bytes
version 15.3
no service pad
service timestamps debug datetime msec localtime
service timestamps log datetime msec localtime
service password-encryption
hostname R-US-RS-WVPN1
boot-start-marker
boot system flash:c1900-universalk9-mz.SPA.153-1.T1.bin
boot system flash:c1900-universalk9-mz.SPA.151-3.T1.bin
boot-end-marker
logging buffered 64000
enable secret 5 *removed*
no aaa new-model
clock timezone CET 1 0
clock summer-time CET recurring last Sun Mar 2:00 last Sun Oct 3:00
errdisable recovery cause udld
errdisable recovery cause bpduguard
errdisable recovery cause rootguard
errdisable recovery cause pagp-flap
errdisable recovery cause dtp-flap
errdisable recovery cause link-flap
errdisable recovery interval 303
ip cef
ip domain name corp.com
ip name-server 10.###.8.21
ip name-server 10.###.8.96
ip inspect dns-timeout 90
ip inspect tcp idle-time 60
ip inspect name fw smtp timeout 120
ip inspect name fw ftp timeout 120
ip inspect name fw realaudio
ip inspect name fw tftp timeout 30
ip inspect name fw udp timeout 30
ip inspect name fw tcp timeout 60
no ipv6 cef
multilink bundle-name authenticated
crypto pki trustpoint TP-self-signed-316595902
enrollment selfsigned
subject-name cn=IOS-Self-Signed-Certificate-316595902
revocation-check none
rsakeypair TP-self-signed-316595902
crypto pki certificate chain TP-self-signed-316595902
certificate self-signed 01
*removed*
        quit
license udi pid CISCO1921/K9 sn FTX153182M8
spanning-tree vlan 229 priority 8192
redundancy
ip ssh version 2
crypto isakmp policy 10
hash md5
authentication pre-share
lifetime 3600
crypto isakmp key *removed* address 70.###.172.142
crypto isakmp key *removed* address 184.###.###.254
crypto isakmp keepalive 35 11
crypto ipsec transform-set FY-WVPN-Tunnel esp-aes esp-md5-hmac
mode tunnel
crypto map vpn 10 ipsec-isakmp
set peer 70.###.172.142
set peer 184.###.###.254
set transform-set FY-WVPN-Tunnel
match address gre-tunnel-list
interface Loopback0
ip address 10.###.0.10 255.255.255.255
interface Tunnel2291
description Primary-TimewarnerTelecom-Ral-FayWVPN1
ip address 10.###.99.26 255.255.255.252
no ip redirects
cdp enable
tunnel source 66.###.161.126
tunnel destination 184.###.###.254
crypto map vpn
interface Tunnel2293
description Primary-TimewarnerTelecom-Ral-FayWVPN2
ip address 10.###.99.154 255.255.255.252
no ip redirects
cdp enable
tunnel source 66.###.161.126
tunnel destination 70.###.172.142
crypto map vpn
interface Embedded-Service-Engine0/0
no ip address
shutdown
interface GigabitEthernet0/0
description TW Telecom/DMVPN1
ip address 66.###.161.126 255.255.255.252
ip access-group Block-Internet in
ip access-group Block-Internet out
duplex auto
speed auto
no cdp enable
crypto map vpn
interface GigabitEthernet0/1
no ip address
duplex auto
speed auto
interface GigabitEthernet0/0/0
switchport access vlan 229
no ip address
interface GigabitEthernet0/0/1
switchport access vlan 229
no ip address
interface GigabitEthernet0/0/2
switchport access vlan 229
no ip address
interface GigabitEthernet0/0/3
description PBX Eth1
switchport access vlan 229
no ip address
interface Vlan1
no ip address
shutdown
interface Vlan229
ip address 10.###.229.253 255.255.255.0
ip helper-address 10.###.231.201
standby 229 ip 10.###.229.254
standby 229 priority 105
standby 229 preempt
router eigrp 100
network 10.0.0.0
ip forward-protocol nd
no ip http server
ip http secure-server
ip route 70.###.172.142 255.255.255.255 66.###.161.125
ip route 184.###.###.254 255.255.255.255 66.###.161.125
ip route 205.###.96.180 255.255.255.252 66.###.161.125
ip access-list extended Block-Internet
permit esp host 66.###.161.126 host 184.###.###.254
permit esp host 184.###.###.254 host 66.###.161.126
permit udp host 66.###.161.126 host 184.###.###.254 eq isakmp
permit udp host 184.###.###.254 host 66.###.161.126 eq isakmp
permit esp host 66.###.161.126 host 70.###.172.142
permit esp host 70.###.172.142 host 66.###.161.126
permit udp host 66.###.161.126 host 70.###.172.142 eq isakmp
permit udp host 70.###.172.142 host 66.###.161.126 eq isakmp
permit icmp host 66.###.161.126 host 184.###.###.254
permit icmp host 184.###.###.254 host 66.###.161.126
permit icmp host 66.###.161.126 host 70.###.172.142
permit icmp host 70.###.172.142 host 66.###.161.126
permit icmp any any echo-reply
permit icmp any any time-exceeded
permit icmp any any packet-too-big
permit icmp any any traceroute
permit icmp any any unreachable
deny   ip any any
deny   icmp any any
ip access-list extended gre-tunnel-list
permit gre host 66.###.161.126 host 184.###.###.254
permit gre host 66.###.161.126 host 70.###.172.142
logging host 10.100.###.254
logging host 10.100.###.246
snmp-server community a RW 20
snmp-server community r RO 20
snmp-server community a RW 20
snmp-server community r RO 20
snmp-server community P_RW RW
snmp-server community P_RO RO
snmp-server enable traps entity-sensor threshold
snmp-server host 10.100.###.246 public
snmp-server host 10.100.###.254 public
access-list 20 permit 10.###.9.3
access-list 20 permit 10.###.8.16
access-list 20 permit 10.100.###.249
access-list 20 permit 10.100.###.254
access-list 20 permit 10.100.###.246
control-plane
banner motd ^CCCCCCC
****************** Warning! Warning! Warning! ********************
This system is restricted to authorized users for business
purposes. Unauthorized access is a violation of the law. This
service may be monitored for administrative and security reasons.
By proceeding, you consent to this monitoring
****************** Warning! Warning! Warning! ********************
^C
line con 0
login local
line aux 0
line 2
no activation-character
no exec
transport preferred none
transport input all
transport output pad telnet rlogin lapb-ta mop udptn v120 ssh
stopbits 1
line vty 0 4
exec-timeout 60 0
password 7 *removed*
login local
transport input ssh
line vty 5 15
exec-timeout 60 0
password 7 *removed*
login local
transport input ssh
scheduler allocate 20000 1000
ntp server 10.###.8.8 prefer
ntp server 10.###.231.200 prefer
ntp server 10.###.8.69
ntp server 10.###.1.6 prefer
end
Router 2
Current configuration : 9013 bytes
version 15.3
no service pad
service timestamps debug datetime msec localtime
service timestamps log datetime msec localtime
service password-encryption
hostname R-US-RS-WVPN2
boot-start-marker
boot system flash:c1900-universalk9-mz.SPA.153-1.T1.bin
boot system flash:c1900-universalk9-mz.SPA.151-3.T1.bin
boot-end-marker
logging buffered 64000
logging console critical
enable secret 5 *removed*
no aaa new-model
clock timezone CET 1 0
clock summer-time CET recurring last Sun Mar 2:00 last Sun Oct 3:00
errdisable recovery cause udld
errdisable recovery cause bpduguard
errdisable recovery cause rootguard
errdisable recovery cause pagp-flap
errdisable recovery cause dtp-flap
errdisable recovery cause link-flap
errdisable recovery interval 303
ip cef
ip domain name corp.mann-hummel.com
ip name-server 10.###.8.21
ip name-server 10.###.8.96
ip inspect dns-timeout 90
ip inspect tcp idle-time 60
ip inspect name fw smtp timeout 120
ip inspect name fw ftp timeout 120
ip inspect name fw realaudio
ip inspect name fw tftp timeout 30
ip inspect name fw udp timeout 30
ip inspect name fw tcp timeout 60
ipv6 multicast rpf use-bgp
no ipv6 cef
multilink bundle-name authenticated
crypto pki trustpoint TP-self-signed-3179596086
enrollment selfsigned
subject-name cn=IOS-Self-Signed-Certificate-3179596086
revocation-check none
rsakeypair TP-self-signed-3179596086
crypto pki certificate chain TP-self-signed-3179596086
certificate self-signed 01
*removed*
        quit
license udi pid CISCO1921/K9 sn FTX153182M2
spanning-tree vlan 229 priority 1###84
redundancy
ip ssh version 2
crypto isakmp policy 10
hash md5
authentication pre-share
lifetime 3600
crypto isakmp key *removed* address 70.###.172.142
crypto isakmp key *removed* address 184.###.###.254
crypto isakmp keepalive 35 11
crypto ipsec transform-set Fay-Ral-WVPN-Tunnel esp-aes esp-md5-hmac
mode tunnel
crypto map vpn 10 ipsec-isakmp
set peer 184.###.###.254
set peer 70.###.172.142
set transform-set Fay-Ral-WVPN-Tunnel
match address gre-tunnel-list
interface Loopback0
ip address 10.###.0.12 255.255.255.255
interface Tunnel2292
description Failover-TimewarnerCable-Ral-Fay-WVPN2
ip address 10.###.99.30 255.255.255.252
no ip redirects
cdp enable
tunnel source 96.###.25.226
tunnel destination 184.###.###.254
crypto map vpn
interface Tunnel2294
description Failover-TimewarnerCable-Ral-Fay-WVPN2
ip address 10.###.99.158 255.255.255.252
no ip redirects
cdp enable
tunnel source 96.###.25.226
tunnel destination 70.###.172.142
crypto map vpn
interface Embedded-Service-Engine0/0
no ip address
shutdown
interface GigabitEthernet0/0
description Fay-Ral WVPN
ip address 96.###.25.226 255.255.255.252
ip access-group Block-Internet in
ip access-group Block-Internet out
duplex auto
speed auto
no cdp enable
crypto map vpn
interface GigabitEthernet0/1
no ip address
shutdown
duplex auto
speed auto
interface GigabitEthernet0/0/0
switchport access vlan 229
no ip address
interface GigabitEthernet0/0/1
switchport access vlan 229
no ip address
interface GigabitEthernet0/0/2
switchport access vlan 229
no ip address
interface GigabitEthernet0/0/3
description PBX Eth2
switchport access vlan 229
no ip address
interface Vlan1
no ip address
shutdown
interface Vlan229
ip address 10.###.229.252 255.255.255.0
ip helper-address 10.###.231.201
standby 229 ip 10.###.229.254
standby 229 preempt
router eigrp 100
network 10.0.0.0
ip forward-protocol nd
no ip http server
ip http secure-server
ip route 70.###.172.142 255.255.255.255 96.###.25.225
ip route 184.###.###.254 255.255.255.255 96.###.25.225
ip route 205.###.96.180 255.255.255.252 66.###.161.125
ip access-list extended Block-Internet
permit esp host 96.###.25.226 host 184.###.###.254
permit esp host 184.###.###.254 host 96.###.25.226
permit udp host 96.###.25.226 host 184.###.###.254 eq isakmp
permit udp host 184.###.###.254 host 96.###.25.226 eq isakmp
permit esp host 96.###.25.226 host 70.###.172.142
permit esp host 70.###.172.142 host 96.###.25.226
permit udp host 96.###.25.226 host 70.###.172.142 eq isakmp
permit udp host 70.###.172.142 host 96.###.25.226 eq isakmp
permit icmp host 96.###.25.226 host 184.###.###.254
permit icmp host 184.###.###.254 host 96.###.25.226
permit icmp host 96.###.25.226 host 70.###.172.142
permit icmp host 70.###.172.142 host 96.###.25.226
permit icmp any any echo-reply
permit icmp any any time-exceeded
permit icmp any any packet-too-big
permit icmp any any traceroute
permit icmp any any unreachable
deny   ip any any
deny   icmp any any
ip access-list extended gre-tunnel-list
permit gre host 96.###.25.226 host 184.###.###.254
permit gre host 96.###.25.226 host 70.###.172.142
logging host 10.100.###.254
logging host 10.100.###.246
snmp-server community P_RW RW
snmp-server community P_RO RO
snmp-server community a RW 20
snmp-server community r RO 20
snmp-server community a RW 20
snmp-server community r RO 20
snmp-server enable traps entity-sensor threshold
snmp-server host 10.100.###.246 public
snmp-server host 10.100.###.254 public
access-list 20 permit 10.###.9.3
access-list 20 permit 10.###.8.16
access-list 20 permit 10.100.###.249
access-list 20 permit 10.100.###.254
access-list 20 permit 10.100.###.246
control-plane
banner motd ^CCCCCC
****************** Warning! Warning! Warning! ********************
This system is restricted to authorized users for business
purposes. Unauthorized access is a violation of the law. This
service may be monitored for administrative and security reasons.
By proceeding, you consent to this monitoring
****************** Warning! Warning! Warning! ********************
^C
line con 0
login local
line aux 0
line 2
no activation-character
no exec
transport preferred none
transport input all
transport output pad telnet rlogin lapb-ta mop udptn v120 ssh
stopbits 1
line vty 0 4
exec-timeout 60 0
password 7 *removed*
login local
transport input ssh
line vty 5 15
exec-timeout 60 0
password 7 *removed*
login local
transport input ssh
scheduler allocate 20000 1000
ntp server 10.###.8.8 prefer
ntp server 10.###.231.200 prefer
ntp server 10.###.8.69
ntp server 10.###.1.6 prefer
end

UPDATE
I have since applied the following config to the tunnel interfaces:
ip mtu 1400
ip tcp adjust-mss 1400
tunnel path-mtu-discovery
This worked and I was able to reset each users PC to default MTU size of 1500, but only until just now. I got a call from a user who explained that he wasn't able to reach some websites, again.
Sure enough, I've just confirmed that all of the users are unable to access the websites any longer.
This is crazy, does anyone have any ideas?

FTTH connection proper MTU Size and Jumbo frames

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