vpc - nexus

[Network Pro]

Hi,

we have the following setup.

ISP  <------- Firewall <----------- Switch

                                          (Vlan100)

                                                  |

                                                  |

                                           Nexus 2----------- Nexus 1

                                                  |         (VPC)     |

                                                  |                       | 

                                                User Switch stack - 3 cisco 2950

                                                           (Vlan 101)

Initally we just had one connection from the switch to the nexus. I configured vpc, thereby giving a secondary connection to each nexus. both nexus are connected using vpc. the end user switch is a stack of 3 2950 cisco switches. for some reason only for a few people, the internet does not seem to work (maybe a switch in the stack) - but when you remove the secondary connection the one of the nexus the internet seems to work for everyone. any thought s?

[Network Pro]

sorry that was just a diagram i got from internet with their ip addressing. I have corrected this to a similar one now

all the svi exits on the l3 switch and both nexus. also there is static route on each nexus pointing to firewall.

I tried vpc on a test switch (gave connections to each nexus) and i cant seem to ping the l3 switch from my pc which was connected to the test switch. and pinging the l3 switch (10.1.1.30) didnt seem to work either from the neuxs (lost 2 packets out of every 5)

so as you said there is a blackhole. now will the peer-gateway problem sort this out or a l3 link between both nexus sort oyt his problem ?

[Network Pro]

any thoughts nikolay and jeye ?

the above is just a representation as the ip address used are different.

so do you think peer-gateway or adding a l3 link  between both nexus would sort the problem ? if we add a l3 link between both nexus will it affect our exisitng network as we have svi on both nexus and l3 wan switch and other sites connected and we run ospf. does this new l3 link need to be advertised into ospf ?

[Jerry Ye]

So, from this post, you are using the L3 switch as your SVIs.

This interface from the "L3 switch" is consider as orphan. If you can share the Nexus 7000 config and the L3 switch, it would be great. I am still confused with topology.

In terms of the ping lost, it is normal. The Nexus has CoPP which will drop ping.

Regards,

jerry

[Network Pro]

hi jerry,

can i have your email address so that i can mail you the actual config with topology. my boss would not like to post hte configs on the internet

thnaks

[Jerry Ye]

Let me send you a private message and you can reply it with the information I am looking for.

Regards,

jerry

[aacole]

Did you get a resolution to this problem?

I am going to look at a network that seems to have the same problem, the next downtime slot is at the end of November amd am doing some reading up on the issue first to prepare.

When I came across this thread I was hoping that it may have had some details of the fix posted, assuming it did get fixed.

[Network Pro]

hi havent sorted this out yet but the resolution is if you have a second link from the switch to nexus (swithport or have both links routed - preferred) would sort the problem out