MAC Address issue in Linux Guest

Hi,
IP address is getting change on every reboot of Linux machine in HyperV environment even we have make it static inside the Linux configuration file.
Any Suggestion ??

Hi Amit,
Can you check whether the MAC address is persistent on the VM?
Configure a static MAC for the VM using VM properties.
Delete the *persistent-net.rules in /etc/udev/rules.d/ and reboot the VM.
Thanks,
Janaka
Janaka Rangama MCT MIEEE MBCS (Please take a moment to Vote as Helpful and/or Mark as Answer, where applicable.)

Similar Messages

MAC address issue----Spearman

Saw your comments on this in the post about the 1.9 bios for neo2platty ....
I can confirm that My MAC address issue was caused by the bios that you sited in your comments....all F's were written to My nvidia lan too...
only solution from what I have read is too rma it...'bummer'
just thought You would like to know.... Your not alone

I had the same problem yesterday and after many hours searching the web I ended up with this post that made me really desperate... But I didn't give up and while trying a new bios flash because of random crashes when in the bios, I noticed the obvious: you can change the MAC address when flashing
use the last version of the dos flasher with the parameters /nvmac:xxxxxxxxxxxx/wb after the name of the bios file; it's explained if you ask the help with the /help parameter. You can find the mac address on a stick on the parallel port.

"task blocked" issue in linux guest

Host: Win 7 Pro 64-bit
VBox: 4.3.12
Guest: Oracle Linux 5.6 64-bit
Every so often I get this popped up on my vbox guest console.
What's more puzzling is I can pretty well predict when its going to happen. Everything else on the host system slows to a crawl. Even to the point of keyboard response delays and long delays even getting task manager fired up. Sometimes the only relief is to shut down the guest, and if I do an ACPI shutdown from the guest console window menu, even that can take several minutes.
I never actually work at the guest console. Instead, use putty to connect to the vm, exactly like I would to connect to my live servers in the data center.
Any ideas on what is going on?

Hi Amit,
Can you check whether the MAC address is persistent on the VM?
Configure a static MAC for the VM using VM properties.
Delete the *persistent-net.rules in /etc/udev/rules.d/ and reboot the VM.
Thanks,
Janaka
Janaka Rangama MCT MIEEE MBCS (Please take a moment to Vote as Helpful and/or Mark as Answer, where applicable.)

Spanning Tree and Admin mac address issues srw2048

Ok, I have a somewhat complex problem and hopefully someone may shed some light or have an idea as to whats wrong.
First the scenario:
I have two Cisco Cat 6509's etherchanneled to each other via two fiber cables. One of these is the STP/RSTP root. I have two SRW2048's.. one trunked to each of these 6509 switches. There is also a trunk between the SRW2048's. All this is to create a redundant topology so that if one of the switches fail's the others can still forward packets to each other. Of course the scenario described is in fact a loop that should be handled by STP/RSTP. I have RSTP enabled on all the switches in the scenario (PV RSTP on the cisco switches as they only do Cisco's brand of per vlan spanning tree). There are 3 vlan's configured on each of the srw2048's (2,55,96). There are corresponding vlan's also on the 6509's. I have put the srw2048's management interface into vlan 2.
The problem:
I need to forward packets between the srw2048's primarily and only use the 6509 that is not the root when a failure happens. I have configured the non-root 6509's spanning tree cost on the etherchannel to be higher then the alternate path through the srw's to the root. I can hook everything up and view the spanning tree and see that the srw2048's interface that goes to the non-root 6509 is blocked, and all other interfaces on the other switches are forwarding. I can in fact ping and get to the admin interface on all the switches. Then for some strange reason the admin interface of the srw2048 plugged into the non-root 6509 stops responding. If I disable either the interface its plugged into on the 6509 or the other srw2048 everything starts working again. Sometimes it responds after many failures for no apparent reason. I looked into the mac-address table on the 6509's and they are conflicting, pointing to each other for the mac-address of the broken srw2048. When I clear the mac-table the admin port comes back for about 5 seconds then again goes dark. When reviewing mac-table on the 6509's they are back to pointing to each other. The odd thing (although I haven't confirmed this completely) is that hosts placed into vlan 2 on that same srw2048 seem to work fine. If there was an STP loop or something misconfigured, I would expect it to effect any host in vlan 2 or the other vlan's for that matter on the srw2048 that stops responding. Alas, I am stuck because I need to manage this switch remotely. My only thought is that for some reason even when the STP status is blocked the broken srw2048 is still sending out arp's of its admin interface and bypassing the STP protocol. I have no way to confirm this, but maybe someone has an idea as to what I'm doing wrong, or otherwise offer a solution. For now, I simply removed vlan 2 from the 6509 that the broken srw2048 is plugged into and everything seems fine.
My apologies for such a long post, but this is somewhat complicated. Thanks in advance for any info.
-Geoff
Message Edited by gmyers on 08-19-2008 10:35 PM

To follow up, I had a ticket open with Linksys about this for about 3 months with no resolution. I submitted packet captures, stp outputs, etc and no luck. I gave up and basically had to revert to a manual failover for redundancy. It's no perfect or fast, but it works every time.
Unless linksys issues a firmware upgrade with this as a fix, I doubt we will be able to ever resolve this on our own.

WRT600N weird MAC Address issue

I've had the Linksys WRT600N for several months. One day the internet connection stopped working, after I power cycled it, I called support and they had me change the router to clone MAC address after that it worked. If I took off the cloned MAC the internet wouldnt work. So I got curious after that and I restored the router the settings file I had backed up previously. I tried my internet connection and everything worked. No clone MAC address, however, after about a month it stopped again. The issue was making sure clone mac address was on. My question is why does that keep happening there shouldnt be a reason that it would need my computers mac if my isp doesnt need me to do thaa. (ISP = Optimium) Has anyone had this problem or know what the cause is?

You have to tell what you did exactly if it did not work.
Generally: many ISPs (most cable ISPs) only grant you a single public IP address, i.e. a single device connected to their service. Most do this by storing the MAC address of the device connected to the modem. If you connect a different device with a different MAC address into the modem they won't accept it. You won't get an IP address. You don't have internet. Only the device with the MAC address stored (or a modified MAC address set to the stored MAC address) will have internet.
Some ISPs reset the stored MAC address if you call them. With a few ISPs this is the only option.
Most ISPs reset the MAC address after a few hours of inactivity or in fixed intervals.
Some ISPs recognize if you reset the modem and reset the MAC address then.
After it is reset you can connect a different device and it will get the IP address.
Now, if your internet at some point does not work and for a test you connect the computer directly to the modem and you get internet then, at that moment you already have locked in MAC address of the computer and you have to use the MAC address clone on the router.
Thus, if you need the MAC address clone or not depends on what you did when exactly after how much time of inactivity when the internet did not work anymore.

4500 VLAN MAC address issue

We are facing an issue with our 4500 switch. It is using the same MAC address for all VLAN interfaces, which is causing a problem with our service provider.
Is there a way to disable this?
Thanks,
Fabián

Fabián,
I'm afraid that's not possible on a 4500:
Supported Platforms for Unique MAC Address Configuration on VLAN or L3 Interfaces for Catalyst Switches
Best regards
Rolf

MAC address issue...old, but have question

I missed all the news about bios 2.5 but anyway did it screw up the MAC address? I flashed it but it never let me into windows saying I didn't have an acpi compliant bios.
I see some things about it messing up the MAC...
If the mac address isn't all zeros is it ok? Or did the bios just change it altogether to a diiferent value?
Sorry for late post about it...I missed it when bios 2.5 out to do my comp being down at the time.

Quote
Originally posted by J*A*G
It looks odd it is like a bunch of 8080808080....maybe I better try the fix.
Uh-yup. You got a busted MAC address. Off to the catacombs with ya! At least the search function runs good now.
Jef

Wlc 2100 mac -address issue

Hi all,
we are using wlc 2106-k9 controller, with mac based authetication for cilents. After few days mac-address database automatically deleted few mac-address. this is not first time it happen twice. we have entered totally 60 mac-address only . It has IOS AIR-WLC2100-K9-7-0-98-218.aes.
Thanks in advance.

I had the same problem yesterday and after many hours searching the web I ended up with this post that made me really desperate... But I didn't give up and while trying a new bios flash because of random crashes when in the bios, I noticed the obvious: you can change the MAC address when flashing
use the last version of the dos flasher with the parameters /nvmac:xxxxxxxxxxxx/wb after the name of the bios file; it's explained if you ask the help with the /help parameter. You can find the mac address on a stick on the parallel port.

Hyper-V on Windows 8.1 is messing with MAC address when sharing my Wifi card

Hello,
I'm using Hyper-V on Windows 8.1 to build a complete SharePoint Development environment.
All of my VM are following this scheme:
a "local" private network shared between the host and all VM, using a static IP address plan (192.168.10.0/24)
a RJ45 external network, attached to my physical ethernet card. This network uses DHCP protocol
a WIFI external network, attached to my wireless network card. This network also use DHCP protocol
When plugged on the ethernet card, I have no issue. Both the host and the guest OSes are getting a valid IP address.
However, when I try to connect on the wireless card, I get some weird errors. Actually, my guest OS are getting the same IP address than the host. This issue an IP address conflict.
Someone else got the same kind of behavior : Windows 8.1
Hyper-V : IP address conflict on Guest OS
I've checked my MAC address plan, and it seems correct.
Using WireShark (a tool I'm not used to I admit), I can see that all DHCP request of the guest os, are sending the host MAC address, and not the guest' one.
Does anyone have an answer to this weird behavior?
Thanks,
steve
Paying back the community for its help by writing articles :
Have a Nice Day.Net Blog

Hi Steve,
Please try the following step and then retry ipconfig /renew in your VM :
1. Configure the WI-FI router to assign a static IP address to the host’s wireless network adapter(the IP should not be in DHCP Pool).
2. On the host, configure the wireless network adapter to use a static IP address. The IP address will be the same address configured in step 1.
3. Using Hyper-V Manager, create an external network switch that is bound to the host’s wireless network adapter
Hope this helps
Best Regards
Elton Ji
We
are trying to better understand customer views on social support experience, so your participation in this
interview project would be greatly appreciated if you have time.
Thanks for helping make community forums a great place.
Hi Elton,
First of all, thanks for your effort.
I will try your suggestion, but even if it works, it won't solve the actual root the issue.
Moreover, it is only relevant if I can control every wireless network I'm connecting to. What about if I travel and I connect with a customer wireless network? what about an hotel wireless network?
As I said, wireshark shows me DHCP requests using the wrong IP address. I strongly believe there's a bug somewhere between the wireless card driver and Hyper-v Mac-Bridge service.
Steve
Paying back the community for its help by writing articles :
Have a Nice Day.Net Blog

Wrong mac address listed in verizon router for a device on my network

Hi folks,
I'm having some routing issues and hope you can help.
I've got the standard verizon actiontec MI424WR-GEN3I router for my standard LAN and then a 2nd router (linksys wrt54g) for a testing environment I set up, to help isolate the traffic. I'm using the LAN to WAN strategy to set up the two networks.
everything seems to be working fine except for the fact that my devices behind the actiontec router cannot ping/access any devices behind the linksys router, but the devices behind the linksys router are able to ping and reach the devices behind the actiontec router.
my actiontec subnet is 192.168.1.X while my linksys subnet is 192.168.2.X. I followed this tutorial on the verizon forum to hopefully get the two networks talking correctly: http://forums.verizon.com/t5/FiOS-Internet/Multiple-routers-and-subnets-can-t-access-across-subnets/...
an issue I see in my actiontec router is that it appears as though the mac address is not correct for what I'd imagine is the WAN port on the linksys router. the actiontec is showing the MAC as 00:13:10:73:72:6a while the sticker on the router itself and through the ARP command in the command prompt shows the MAC for the linksys router as 00:13:10:73:72:69. I've power cycled both routers 2x and nothing has changed. I currently have the ethernet cable that goes from my actiontec to the linksys unplugged so hopefully it'll drop from network list eventually and reaquire an address when it's hooked back up, hopefully correcting the wrong MAC address issue.
I'm a bit perplexed as to why I can get out to the internet just fine on my 192.168.2.X network with a botched MAC address, but I can't ping the network that's just a hop away...even after following the guide mentioned above.
any ideas here?

You can release the address yourself. It's a function under my network, network connections, broadband connection (whichever one is connected), configure connection
dhcp lease Release
Then recycle the router
After you set up the static route did the ping work? - ensure that you have icmp enabled on the linksys. If you don't get a ping response it indicates an issue with the static route rule.

Router cannot see Hyper-V Guest MAC address

Greeting,
I have been trying to build a server on Hyper-V, on a host running Windows Server 2012 R2, and a wireless adapter is used.
A virtual switch was created as external, connected to the host's wireless adapter.
The guest OS is Debian 7, and the problem is it's unable to use DHCP to connect to the internet.
I have to manually specific an IP address and the subnet mask in order to access the internet in the Guest OS, say 192.168.0.50. And I set port forward to this IP for external connection to the guest, but then sometimes I cannot connect; without doing anything
it restores the connection after a while. At the same time I am keeping the MSRDP connection to tthe host so the host has not lost connecting to the internet.
When the server on Guest is not accessible from the web, I can still connect to the server within the host machine by typing the lan IP of the guest: 192.168.0.50
On checking the router, I found that two IP address 192.168.0.50 (Guest OS) and 192.168.0.15 (Host) are sharing the same MAC address (of the wireless card). It means the MAC address of the Guest OS is not seen by the router, and I suppose this is the root
for the instability.
Would you have any ideas about the situation, and suggested solution?
Thank you.

An update to my issue:
Just realized the possible cause: the (freaking) router is dropping inactive machine.
Basically the DHCP issue is not solved, but it doesn't seem to be a cause after all, as long as I manually assign the IP it works, even having the 2 IPs with the same MAC on the ARP table on router. (Host connection drop has to be further investigated).
As I found that the loss of connection actually happens after a while I don't touch the web server on VM, the longer I leave it idle the more likely I cannot connect to it again. The situation is like a prolonged loading when trying to access a website,
where sometimes you can connect after a while, or you never.
What's weird is, if I somehow manage to connect to the idle VM server by multiple attempts, and that after I have restored the connection, I can reconnect to the server from another computer very quickly without any significant loading time.
On some quick searches, I found someone using Linksys router is suffering from a similar situation as I do:
http://serverfault.com/questions/522448/application-request-routing-on-a-hyper-v-guest-intermittently-stops
So what I can try are basically 3 ways
-Change the router, not viable as I don't own it.
-Insert a wireless bridge in between
-Do something with Debian, making it periodically generate network request to the internet to keep the connection alive
Any ideas about my observation, and maybe possible solutions?
Thank you for reading.

LAN and WAN share the same MAC address -- could this be a security issue?

When I bought the AEBS(n), I was a bit surprised to see only one ethernet MAC address listed (on bottom of unit, or was it in config utility?), in addition to wireless MAC. My main router has two ethernet MACs.
So last nite, I investigated. I confirmed my suspicion that both the WAN port and the LAN ports share the same MAC address! My setup has the AEBS WAN port plugged into my home LAN's main router, and a Linux machine plugged into a LAN port of the AEBS.
View of AEBS WAN side (from main router at 192.168.1.1)
ii# arp
Seconds IP Address MAC Address
734 66.130.224.1 001120A87AF5 -- ISP router
789 192.168.1.21 0016CBC430A6 -- AEBS WAN port
28 192.168.1.33 0010DC47DC53 -- home PC
824 192.168.1.73 00065BB2F295 -- work PC
View of AEBS LAN side (from a Linux box at 10.0.1.41)
root@LKG7CAE25 # cat /proc/net/arp
IP address HW type Flags HW address Mask Device
10.0.1.1 0x1 0x2 00:16:CB:C4:30:A6 * eth0
10.0.1.1 on the LAN side of AEBS and 192.168.1.21 on the WAN side of the AEBS both use the same MAC address, 00:16:CB:C4:30:A6.
I tried to provoke some leakage between the two sides (for example with broadcast packets), but haven't been able to do it so yet. Perhaps the switch in front of the eth MAC has enough smarts to keep the two subnets separate? Still it sort of worries me, if I used the AEBS as my only router, that both WAN and LAN go thru the same ethernet MAC (same h/w). I browsed here but found no discussion on this.
Comments anyone?

.... This is why there are separate MAC addresses
for ethernet and wireless, they are physically
different networks. In the case of the WAN/LAN, both
are ethernet-type networks but are physically
distinct (this is the purpose of a router like the
AEBS), so having the same MAC address on both sides
won't cause any sort of collision nor should it be
possible to leak across networks. MAC addresses can't
be used for routing beyond the physical network.
If it is indeed two different NICs sharing a single MAC, then indeed it is not an issue as you would never want to connect these two NICs together. But is it really two NICs?
My worry is that these two subnets are on the same physical network, with some magic going on to keep them separate anyway. Do we have some picture of AEBS internals? Maybe that would answer the question...

WiFi issue with MAC address

I've been using MAC filtering as part of my home network wireless security for years. This means inputting the MAC address of every device and computer that I want to have connect to my network. So I get my new WiFi + 3G iPad on May 28th and look in Settings to find the MAC address so I can input it into my router info. The router (D-Link) says that it's not a valid MAC format, presumably because it begins with E8 instead of the 00 that all my other devices have. I ended up having to disable MAC address filtering in order to have my iPad connect to my WiFi network. Does anybody have any comments or ideas about how I can get the router to recognize a MAC that begins E8:06 etc.?
Would appreciate any help. Thanks.
Glenys

I am using MAC filtering on my network using a Linksys router (WRT300N) and had no problems adding our iPad to the MAC table. Also, if I'm not mistaken, the first portion of a MAC address is unique to the manufacturer, so unless all of your wireless devices are from the same manufacturer (at least the wireless component of the device), then it isn't likely that all of your MAC addresses will start with the same digits. Make sure when you enter the MAC address that you include the colon in between each pair. My Linksys won't accept the MAC address without them. As someone else recommended, you may also want to see if there is a firmware update for your router that addresses this issue. Good Luck.

Help required - mac address table, virtual pc/ip addressing issue

Hi, hope someone out there can help?
This is the scenario
SW1 (WS-C2960G-48TC-L) port gig0/1 has a PC connected to it with ip address 10.182.8.6 and a Virtual IP address 10.182.8.107
SW2 (WS-C2960-24TT-L) port gig 0/1 has a PC connected to it with ip address 10.182.8.106
The system is designed so that if there is an issue with the PC connected to SW1, the PC on SW2 will take over the Virtual IP address and continue working.
We have a couple of other PC's in different subnets to the above PC's that use the Virtual IP (VIP) address to communicate with the PC that is 'on line'.
Unfortunately, the vendors software doesn't currently gratuitously refresh the arp to advertise the change of mac address for the VIP.
Is there anyway we can get the 2 dcnsw to 'refresh' on a regular time period to capture when the VIP changes to the other PC?

Hi Stephen
Without meaning to sound rude, the software which uses a VIP is not very well designed if it is not capable of sending a Gratuitous ARP one the Active one fails.
The default ARP cache timeout is 4 hours so an ARP entry will remain in the table and once the timeout is up, the switch will send an ARP to check if the device is still alive and if not, remove the entry from the table.
You could look at reducing the ARP timeout on a per port basis:
#interface gi1/0/1
#arp timeout 60
This will change the ARP cache timeout to 60 seconds for that port but having not used this before, I am not 100% this will address your issue. I would not advise trying to change the global ARP cache timeout for a production switch as this will increase ARP traffic and could cause problems if reduced to a small value.

Linux client MAC address getting failure (Mr. Francois)

Hi Mr.Francois
I am using your client information form. Thank you.
But in Linux client
shows
IP & MAC addresses are blank
Any idea !
Regards

Because you did not provide details about which Forms version or client platform you are using it will be difficult to offer specifics. However, if you are using Forms 10.1.2.3 or newer, I would recommend trying to run the WebUtil demo form as it includes functionality to capture the client details. You can download the WebUtil demo from here:
http://www.oracle.com/technetwork/developer-tools/forms/downloads/index.html
It is listed under Forms 11g Demos, but the WebUtil demo is compatible with version 10 and newer. If you have never used this demo (or WebUtil) before, be aware that some features only work on Windows clients. Additionally, some features only work on Windows (32bit) clients.

MAC Address issue in Linux Guest

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