Cisco SRP 540 Series Router custom Dynamic DNS

Hello,
I'm wondering if there is a possibility to get my homepage provider's custom dynamic DNS service working on my Cisco SRP541W Router as I'd not like to be forced to sign up for either DynDNS or TZO which are available through the web frontend.

Hi there,
Sorry for the delay in replying to this. Must have missed it the first time around.
Anyway, I'm afraid the only DDNS providers supported natively by the SRP500 platform are DynDNS and TZO. Having said that, many if not most DDNS providers either have or support the use of a client running on a device behind the router, so that might be a workaround for you. There are a few open sourced generic clients out there that are pretty versatile as well.
Cheers,
Dave.

Similar Messages

IPv6 on CIsco 7200 VXR series router

Dear Friends,
I want to know, whether cisco 7200vxr router support ipv6? I want to use both ipv4 and ipv6. In that case whats about the performance.
Do i need IOS upgradation to acheive this implementation.

Hi -
Our s/w development group is in the process of implementing ipv6 support in our products, and would like to use our Cisco 2650XM running ITP s/w for ipv6 interoperability tests.
However, it appears that ipv6 is not supported in this s/w version:
ITP1#sh version
Cisco IOS Software, C2600 Software (C2600-ITPK9-M), Version 12.4(15)SW2, RELEASE SOFTWARE (fc3)
Technical Support: http://www.cisco.com/techsupport
Copyright (c) 1986-2008 by Cisco Systems, Inc.
Compiled Tue 23-Sep-08 19:48 by prod_rel_team
ROM: System Bootstrap, Version 12.2(7r) [cmong 7r], RELEASE SOFTWARE (fc1)
ITP1#config
Configuring from terminal, memory, or network [terminal]?
Enter configuration commands, one per line. End with CNTL/Z.
ITP1(config)#ipv6 ?
% Unrecognized command
My question is: Can I use this s/w version on the 2650XM in an ipv6 network? Do I need to upgrade the s/w?
Thanks,
Matt

Use an SRP 520 or 540 series to limit download.

Hello there,
I have an SRP 527 and I wish to connect this to my shop as that this has the features where I can create a multiple WiFi SSIDs.
That has been created successfully and quite easily however what I wanted to do is to limit data dowload to my customers because free WiFi is not really free WiFi.
This would be like an Internet Cafe scenario where my customers come in and have their services attended to, while they are waiting, they can connect using the Free WiFi available basically for Facebook, twitter, e-mails or web browsing however I wish to avoid massive downloads that will be costly to me.
I also wish to upgrade to the SRP 540 series and I know the programming is quite different however the same for that?
Can anyone please help???
Kindest Regards

Hi Paul,
The SRP500 isn't able to control download volume on a per user basis. You can restrict access to specific websites or application if you wish using the Internet Access Control feature under Network Setup > Firewall. You can also use this feature to block any access to the Internet outside of your business hours if you wish.
The web interface for the SRP540 is practically identical to that of the SRP520. The SRP540 also includes a Guest WiFi feature that allows you to limit guest access with a password and allow them a set period of time to use the service.
Regards,
Andy

Question about setting up rdp using a cisco 800 series router

HI there,
I am currently in school for networking. One co-op placement I went too handed me a cisco 800 series router to practice my routing skills on. I am trying to setup RDP so I can access my server from outside my internal network. I ran this following acl command to do it.
ip nat inside source static tcp server IP address port# cable modem IP port # extendable.
My question here is, my cable modem will occasionally hand out a different IP since it has DCHP. I cannot turn DHCP off in my cable modem. So is there a way I can set this up to use a dynamic IP from my modem so I alwasy have access to it or every time my modem changes the IP address do I have to go in and modify this acl?

Configure DDNS ( Dynamic DNS ) on the router. For this you need to register with a DDNS provider. Go to
http://www.no-ip.com/ . they provide free reliable service.
With DDNS, Once your router gets a DHCP address from your ISP , it will dynamically update the DNS name record. For example if you register you routers name as, "myrouter.no-ip.org", from there onwards whatever the IP your router gets, you can refer to that by this name.
So do as what Paolo said regarding using interface instead of ip, and register with the DDNS and you are good to go..
Hope this helps
Please rate this post if helpful..
Thanks
Shamal

Trying to Download a Software Image to Cisco 2800 series router through TFTP Using the tftpdnld ROMmon Command

Trying to Download a Software Image to Cisco 2800 series router through TFTP Using the tftpdnld ROMmon Command
and I am getting an Error , I cant figure out what I am doing wrong. I have also pasted my display down here can someone help me out, thanks in advance, I am still new to this utility.
My questions are How do you direct this utility to point to the desktop or the TFTP folder
does FE_PORT: Fast Ethernet 0 imply or point to Fa0/0 on my router
My router is suppose to have 10.0.0.3 255.0.0.0
Gateway of 10.0.0.1 255.0.0.0
My TFTP Server 10.0.0.2 255.0.0.0
How do I get the MAC address of the Router or the TFTP Server and which one is required?
my Ethernet port is 100Mb/Sec I cant tell whether it is full duplex or not so How do i set this FE_SPEED_MODE: Auto???
=====================================================================================
rommon 10 >
rommon 10 > set
PS1=rommon ! >
FE_PORT=0
WARM_REBOOT=
RET_2_RTS=20:35:55 UTC Thu Sep 25 2014
BSI=0
RET_2_RCALTS=
RANDOM_NUM=1600357627
?=0
IP_ADDRESS=10.0.0.3
IP_SUBNET_MASK=255.0.0.0
DEFAULT_GATEWAY=10.0.0.1
TFTP_SERVER=10.0.0.2
TFTP_FILE=
rommon 11 > TFTP_FILE=c2800nm-adventerprisek9-mz.124-24.T4
rommon 12 > TFTP_CHECKSUM=0
rommon 13 > SET
monitor: command "SET" not found
rommon 14 > set
PS1=rommon ! >
FE_PORT=0
WARM_REBOOT=
RET_2_RTS=20:35:55 UTC Thu Sep 25 2014
BSI=0
RET_2_RCALTS=
RANDOM_NUM=1600357627
IP_ADDRESS=10.0.0.3
IP_SUBNET_MASK=255.0.0.0
DEFAULT_GATEWAY=10.0.0.1
TFTP_SERVER=10.0.0.2
?=0
TFTP_FILE=c2800nm-adventerprisek9-mz.124-24.T4
TFTP_CHECKSUM=0
rommon 15 > tftpdnld
          IP_ADDRESS: 10.0.0.3
      IP_SUBNET_MASK: 255.0.0.0
     DEFAULT_GATEWAY: 10.0.0.1
         TFTP_SERVER: 10.0.0.2
           TFTP_FILE: c2800nm-adventerprisek9-mz.124-24.T4
        TFTP_VERBOSE: Progress
    TFTP_RETRY_COUNT: 18
        TFTP_TIMEOUT: 7200
       TFTP_CHECKSUM: No
        TFTP_MACADDR: 30:37:a6:49:35:a8
             FE_PORT: Fast Ethernet 0
       FE_SPEED_MODE: Auto
Invoke this command for disaster recovery only.
WARNING: all existing data in all partitions on flash: will be lost!
Do you wish to continue? y/n: [n]: y
ARP: address resolution for 10.0.0.2 timed out.
ARP failed with failure code 1. TFTP transfer aborted.
TFTP: Operation terminated prematurely.
rommon 16 >       " not found
rommon 17 >FE_SPEED_MODE=2
variable name contains illegal (non-printable) characters
rommon
rommon 18 > set
PS1=rommon ! >
FE_PORT=0
WARM_REBOOT=
RET_2_RTS=20:35:55 UTC Thu Sep 25 2014
BSI=0
RET_2_RCALTS=
RANDOM_NUM=1600357627
IP_ADDRESS=10.0.0.3
IP_SUBNET_MASK=255.0.0.0
DEFAULT_GATEWAY=10.0.0.1
TFTP_SERVER=10.0.0.2
TFTP_FILE=c2800nm-adventerprisek9-mz.124-24.T4
TFTP_CHECKSUM=0
?=0
rommon 19 > tftpdnld [ur]
usage: tftpdnld [-hr]
Use this command for disaster recovery only to recover an image via TFTP.
Monitor variables are used to set up parameters for the transfer.
(Syntax: "VARIABLE_NAME=value" and use "set" to show current variables.)
"ctrl-c" or "break" stops the transfer before flash erase begins.
The following variables are REQUIRED to be set for tftpdnld:
            IP_ADDRESS: The IP address for this unit
        IP_SUBNET_MASK: The subnet mask for this unit
       DEFAULT_GATEWAY: The default gateway for this unit
           TFTP_SERVER: The IP address of the server to fetch from
             TFTP_FILE: The filename to fetch
The following variables are OPTIONAL:
          TFTP_VERBOSE: Print setting. 0=quiet, 1=progress(default), 2=verbose
      TFTP_RETRY_COUNT: Retry count for ARP and TFTP (default=18)
          TFTP_TIMEOUT: Overall timeout of operation in seconds (default=7200)
         TFTP_CHECKSUM: Perform checksum test on image, 0=no, 1=yes (default=1)
          TFTP_MACADDR: The MAC address for this unit
               FE_PORT: 0= (default), 1
         FE_SPEED_MODE: 0=10/hdx, 1=10/fdx, 2=100/hdx, 3=100/fdx,
                        5=Auto (default)
      TFTP_DESTINATION: The flash destination device for the file
                        flash:(default), usbflash0:, usbflash1:
Command line options:
   -h: this help screen
   -r: do not write flash, load to DRAM only and launch image
rommon 20 > tftpdnld
          IP_ADDRESS: 10.0.0.3
      IP_SUBNET_MASK: 255.0.0.0
     DEFAULT_GATEWAY: 10.0.0.1
         TFTP_SERVER: 10.0.0.2
           TFTP_FILE: c2800nm-adventerprisek9-mz.124-24.T4
        TFTP_VERBOSE: Progress
    TFTP_RETRY_COUNT: 18
        TFTP_TIMEOUT: 7200
       TFTP_CHECKSUM: No
        TFTP_MACADDR: 30:37:a6:49:35:a8
             FE_PORT: Fast Ethernet 0
       FE_SPEED_MODE: Auto
Invoke this command for disaster recovery only.
WARNING: all existing data in all partitions on flash: will be lost!
Do you wish to continue? y/n: [n]: y
ARP: address resolution for 10.0.0.2 timed out.
ARP failed with failure code 1. TFTP transfer aborted.
TFTP: Operation terminated prematurely.
rommon 21 >

What I notice in the original post is this error
ARP: address resolution for 10.0.0.2 timed out.
which says that the router is looking for the 10.0.0.2 server but not getting response to its arp request. Can the original poster clarify for us how the device that has the image file is connected to the router that has the problem? Also what kind of device is 10.0.0.2? Is it a PC running TFTP server software or is it something else?
HTH
Rick

How to bridge a linksys cisco E1200 series router?

I have recently purchased a linksys cisco E1200 series router and would like to know how to bridge the connection to my xbox

purchase 881w, get rid of linksys. That should do it.
Sent from Cisco Technical Support iPad App

Cisco 2600 series router and cable modems

Hi everyone, I am just about to get started preparing for my CCNA... I am looking to pick up some used Cisco 2600 series routers to set up a home lab. I am wondering if it is possible to connect a cable modem directly to a 2600 series router? If so, do I need a certain type of WIC? I want to go from my cable modem, to a router, to my switch. Thanks in advance!

Hi,
Yes you can, using the Ethernet port on the cable modem, you can connect the cable modem to the router 2600, and the 2600 comes with builtin ethernet or fastethernet (according to your platform).
HTH,
Mohammed Mahmoud.

License on the Cisco 3900 Series router.

I am trying to understand what does the "data" license exactly do on the Cisco 3900 series router. What I understood is that the data license supports "MPLS.ATM. Multiprotocol support".
Question is is a do not have this license will I not be able to run BGP, EIGRP and terminate service provider links?
Technology Package License Information for Module:'c3900e'
Technology    Technology-package                  Technology-package
              Current              Type           Next reboot
ipbase        ipbasek9             Permanent      ipbasek9
security      securityk9           Permanent      securityk9
uc            None                 None           None
data          None                 None           None
NtwkEss       None                 None           None
CollabPro     None                 None           None
Configuration register is 0x2102
Thanks,
Nik

I think WAAS express is one of the technologies you will lose out on. Amongst other advanced features. See link below.
http://www.cisco.com/c/en/us/products/collateral/cloud-systems-management/software-activation-on-integrated-services-routers-isr/white_paper_c11_556985.html
EDIT: And performance routing.

NetConfig issue wrt Cisco 3900 Series Router

Hi Cisco;
I can't able to configure my Cisco 3900 series Router via NetConfig tool. While I am able to Configure all other Routers (7600, & 2800) and Switchs (6500, 3700, 3560). I can accessable 3900 Series Router via Inventory Collection, Sync Archieve, Campus Manager, DFM and etc.
I have Cisco LMS 3.2 with RME 4.3 & using SNMPV3.
Thanks for your support.
Best regards;
Shoaib Ahmed

Hi Clarke;
Please find the requested Screen Shot.
Actully my problem is that, I can't configure my Cisco 3945 Routers (Shows not applicable devices) via NetConfig tool. I can use other tools like Sync archieve and etc is working fine for these 3945 routers.
Best regards;
Shoaib Ahmed

Configuring New Interface and NAT on Cisco 1900 Series Router.

Hello Cisco Team,
am asking for advise on how to how setup NAT rules and overload on my 2nd interface on my cisco 1900 series router,am not sure where am getting it wrong.
my router has 2 interface, interface one has IP address 10.5.5.5X and plugs into my ASA firwall and into my switch and works just fine.
i have just configured my second Interface with a new IP 172.16.0.X- i want to NAT my new IP address to our public IP address which is 41.77.X.X
my configuration so far are as follows.
GigabitEthernet0/0 172.16.0.X YES manual up up - Not working
GigabitEthernet0/1 10.5.5.X YES NVRAM up up- this works fine
GigabitEthernet0/0/0 41.77.X.X YES NVRAM up up

Hello Jon,
Thanks for your feedback, my router configuration are as follows.
interface GigabitEthernet0/0
description WL2504
ip address 172.16.0.2 255.255.254.0
duplex auto
speed auto
interface GigabitEthernet0/1
description WAN
ip address 10.55.55.2 255.255.255.252
ip nat inside
ip virtual-reassembly in
duplex auto
speed auto
interface GigabitEthernet0/0/0
description LINK TO CLT INTERNET
ip address 41.X.X.130 255.255.255.248
ip nat outside
ip virtual-reassembly in
duplex full
speed 100
media-type sfp
ip forward-protocol nd
no ip http server
no ip http secure-server
ip nat inside source list 1 interface GigabitEthernet0/0/0 overload
ip route 0.0.0.0 0.0.0.0 41.X.X.129
ip route 41.X.X.136 255.255.255.248 10.55.55.1
ip route 192.168.0.0 255.255.255.0 10.55.55.1
access-list 1 permit 10.55.55.0 0.0.0.255
access-list 1 permit 192.168.0.0 0.0.0.255
access-list 1 permit 192.168.1.0 0.0.0.255
from the router interface  interface GigabitEthernet0/0- I will connect it to my wireless Controller WL 2504

IOs for cisco 1900 series router

Hi,
Kindly provide me the IOS version (cisco 1900 router) which can fix the below listed Bugs,
Cisco IOS TCP Listener Crafted Packets Remote DoS (CSCek37177)
Cisco Multiple Devices Crafted IP Option Remote Code Execution (CSCeh52410)
Cisco IOS System Timers Remote Overflow (CSCei61732)
Cisco IOS Secure Shell Server TACACS+ Multiple DoS (CSCed65778, CSCed65285)
Cisco IOS IKE XAUTH ISAKMP IPSec SA Establish Authentication Bypass(CSCeg00277)
Cisco IOS Telnet Service DoS (CSCef46191)
Cisco IOS H.323 Protocol Implementation Flaws Cisco IOS Malformed IPv4 Packet Remote DoS Cisco SSH2 Server/Client Malformed Packet Remote DoS (CSCdz60229, CSCdy87221, CSCdu75477)
Cisco IOS SSH Large Packet CPU Consumption DoS (CSCdw33027) Cisco SIP Crafted INVITE Message Handling DoS (CSCdz39284, CSCdz41124) Cisco IOS Data-link Switching (DLSw) Capabilities Exchange Remote DoS (CSCsf28840)
Cisco IOS AAA RADIUS Long Username Authentication Bypass (CSCee45312)
Cisco IOS TCLSH AAA Command Authorization Bypass (CSCeh73049)
Cisco IOS MMP Stack Group Bidding Protocol (SGBP) Crafted UDP Packet Remote DoS (CSCsb11124)
Cisco IOS IPv6 Packet Processing Arbitrary Code Execution (CSCef68324)
Cisco IOS Malformed BGP Packet Processing Remote DoS (CSCee67450)
Cisco IOS Multi Protocol Label Switching (MPLS) Packet Remote DoS (CSCeb56909)
Cisco IOS IPv6 Packet Processing Remote DoS (CSCed40933)
Cisco IOS SCCP Control Protocol Malformed Message DoS (CSCee08584)
Cisco IOS OSPF Packet Handling DoS (CSCec16481) Cisco IOS ARP Table Overwrite DoS (CSCdu81936)
Regards,
Bala

Hi,
The Current running IOS version is 12.2(4)T7. I tried through bug toolkit. but i couldn't able to consolidate the IOS to fix these bugs.
Regards,
A.Bala
leolaohoo wrote at Tue Jan 25 02:20:52 GMT+05:30 2011:
>Balakrishnan Appavu,
>
>A new message was posted in the Discussion thread "IOs for cisco 1900 series router":
>
>https://supportforums.cisco.com/message/3277195#3277195
>
>Author : leolaohoo
>Profile : https://supportforums.cisco.com/people/leolaohoo
>
>Message:

RV320 Dynamic DNS failing

I have an RV320 I am testing in order to determine if it's suitable for use in the company I work for. We have several remote offices, and will be using IPSEC tunnels, VPN for IT troubleshooting and other features.
Dynamic DNS is returning
"Authorization failed(username or password)." error, although I think it's properly configured and works on
error, although I think it's properly configured and works on other firewall/router units. I have reentered the user, password and domain several times, each time it returns the same error.
Can anyone provide insight into the problem?
I also notice the options do not seem to include any way to use a Custom DNS, that is instead of xxx.dyndns.org it would be myhost.TLD. We have a bunch of xxx.dyndns.org, but do have a few myhost.tld. I hope this is something that could be fixed.
Thanks,
Jeff

Hi Jeff,
I think that the issue is that the PW is too long. I recall a case a while back where a customer had a passord over 20 characters and he had to shorten it. My recollection is not great, but I think that 18 was the limit. A feature request was made to lengthen the password field but no change was made due to hardware or maybe OS limitation. I think that the router was the RV042, which has similar code to the RV320. Sorry I can't be more specific. I would try changing the password at least temporarily to see if it works.
If you would like to make a feature request, please call support and open a case.
www.cisco.com/go/sbsc
- Marty

External Mgmt Address - DHCP/Dynamic DNS

Hi,
My customer is looking to assign the 'External Mgmt Addresses' for their B Series Server Blades (KVM) via DHCP and dynamic DNS instead of an statically defined pool.
Appreciate if someone can confirm if this possible?
Kind Regards, Paul

Hi Robinson,
How are you? Ip address for KVM managament can only be assigned statically direclty to the CIMC or be assigned via a ip pool.
See link below
Managament Ip Addresses (UCS 2.1)
http://www.cisco.com/en/US/docs/unified_computing/ucs/sw/gui/config/guide/2.1/b_UCSM_GUI_Configuration_Guide_2_1_chapter_011101.html#concept_8D1CF1E427424A8AA1ED7E26B31B9227

Cisco or Linksys DSL router that will work with Windows XP Pro?

Any suggestions for a CISCO or LINKSYS DSL router to replace a Zyxel (Century Link) PK5001Z? System is Windows XP Pro, 20 wireless and wired devices connected (including 6 CISCO WVC210 IP cameras ). The Zyxel forwards as many ports as I want, but will only open a limited number of the ports. This limits my access thru the internet (local network sees all cameras). Zyxel support is unable to help.

Hi Edward, if you're looking for a modem/router combo device, Cisco offers the SRP500 series. However this product is EOS/EOL. The small business product line does not have any other DSL termination router aside the SRP series. If your goal is to use a DSL modem and then have a router, you may want to consider RV325 router as it is very feature rich and quite robust.
-Tom
Please mark answered for helpful posts

Ask the Expert: Different Flavors and Design with vPC on Cisco Nexus 5000 Series Switches

Welcome to the Cisco® Support Community Ask the Expert conversation. This is an opportunity to learn and ask questions about Cisco® NX-OS.
The biggest limitation to a classic port channel communication is that the port channel operates only between two devices. To overcome this limitation, Cisco NX-OS has a technology called virtual port channel (vPC). A pair of switches acting as a vPC peer endpoint looks like a single logical entity to port channel attached devices. The two devices that act as the logical port channel endpoint are actually two separate devices. This setup has the benefits of hardware redundancy combined with the benefits offered by a port channel, for example, loop management.
vPC technology is the main factor for success of Cisco Nexus® data center switches such as the Cisco Nexus 5000 Series, Nexus 7000 Series, and Nexus 2000 Series Switches.
This event is focused on discussing all possible types of vPC along-with best practices, failure scenarios, Cisco Technical Assistance Center (TAC) recommendations and troubleshooting
Vishal Mehta is a customer support engineer for the Cisco Data Center Server Virtualization Technical Assistance Center (TAC) team based in San Jose, California. He has been working in TAC for the past 3 years with a primary focus on data center technologies, such as the Cisco Nexus 5000 Series Switches, Cisco Unified Computing System™ (Cisco UCS®), Cisco Nexus 1000V Switch, and virtualization. He presented at Cisco Live in Orlando 2013 and will present at Cisco Live Milan 2014 (BRKCOM-3003, BRKDCT-3444, and LABDCT-2333). He holds a master’s degree from Rutgers University in electrical and computer engineering and has CCIE® certification (number 37139) in routing and switching, and service provider.
Nimit Pathak is a customer support engineer for the Cisco Data Center Server Virtualization TAC team based in San Jose, California, with primary focus on data center technologies, such as Cisco UCS, the Cisco Nexus 1000v Switch, and virtualization. Nimit holds a master's degree in electrical engineering from Bridgeport University, has CCNA® and CCNP® Nimit is also working on a Cisco data center CCIE® certification While also pursuing an MBA degree from Santa Clara University.
Remember to use the rating system to let Vishal and Nimit know if you have received an adequate response.
Because of the volume expected during this event, Vishal and Nimit might not be able to answer every question. Remember that you can continue the conversation in the Network Infrastructure Community, under the subcommunity LAN, Switching & Routing, shortly after the event. This event lasts through August 29, 2014. Visit this forum often to view responses to your questions and the questions of other Cisco Support Community members.

Hello Gustavo
Please see my responses to your questions:
Yes almost all routing protocols use Multicast to establish adjacencies. We are dealing with two different type of traffic –Control Plane and Data Plane.
Control Plane: To establish Routing adjacency, the first packet (hello) is punted to CPU. So in the case of triangle routed VPC topology as specified on the Operations Guide Link, multicast for routing adjacencies will work. The hellos packets will be exchanged across all 3 routers and adjacency will be formed over VPC links
http://www.cisco.com/c/en/us/td/docs/switches/datacenter/nexus5000/sw/operations/n5k_L3_w_vpc_5500platform.html#wp999181
Now for Data Plane we have two types of traffic – Unicast and Multicast.
The Unicast traffic will not have any forwarding issues, but because the Layer 3 ECMP and port channel run independent hash calculations there is a possibility that when the Layer 3 ECMP chooses N5k-1 as the Layer 3 next hop for a destination address while the port channel hashing chooses the physical link toward N5k-2. In this scenario,N5k-2 receives packets from R with the N5k-1 MAC as the destination MAC.
Sending traffic over the peer-link to the correct gateway is acceptable for data forwarding, but it is suboptimal because it makes traffic cross the peer link when the traffic could be routed directly.
For that topology, Multicast Traffic might have complete traffic loss due to the fact that when a PIM router is connected to Cisco Nexus 5500 Platform switches in a vPC topology, the PIM join messages are received only by one switch. The multicast data might be received by the other switch.
The Loop avoidance works little different across Nexus 5000 and Nexus 7000.
Similarity: For both products, loop avoidance is possible due to VSL bit
The VSL bit is set in the DBUS header internal to the Nexus.
It is not something that is set in the ethernet packet that can be identified. The VSL bit is set on the port asic for the port used for the vPC peer link, so if you have Nexus A and Nexus B configured for vPC and a packet leaves Nexus A towards Nexus B, Nexus B will set the VSL bit on the ingress port ASIC. This is not something that would traverse the peer link.
This mechanism is used for loop prevention within the chassis.
The idea being that if the port came in the peer link from the vPC peer, the system makes the assumption that the vPC peer would have forwarded this packet out the vPC-enabled port-channels towards the end device, so the egress vpc interface's port-asic will filter the packet on egress.
Differences: In Nexus 5000 when it has to do L3-to-L2 lookup for forwarding traffic, the VSL bit is cleared and so the traffic is not dropped as compared to Nexus 7000 and Nexus 3000.
It still does loop prevention but the L3-to-L2 lookup is different in Nexus 5000 and Nexus 7000.
For more details please see below presentation:
https://supportforums.cisco.com/sites/default/files/session_14-_nexus.pdf
DCI Scenario: If 2 pairs are of Nexus 5000 then separation of L3/L2 links is not needed.
But in most scenarios I have seen pair of Nexus 5000 with pair of Nexus 7000 over DCI or 2 pairs of Nexus 7000 over DCI. If Nexus 7000 are used then L3 and L2 links are required for sure as mentioned on above presentation link.
Let us know if you have further questions.
Thanks,
Vishal

Cisco SRP 540 Series Router custom Dynamic DNS

Similar Messages

Maybe you are looking for