ip default next-hop Command on Nexus Series Switches or other switch

[2swat]

Description: Recently, I came across information indicating that on Nexus3000 series switches, the default route takes precedence over the next hop set by the "ip default next-hop" operator. This observation was made through the following Bug ID: CSCvg21631.

Situation: Unfortunately, I mistakenly selected a Nexus3000 series switch, only to discover that the "ip default next-hop" command does not function as expected. Despite having a default gateway configured in the main routing table, this command fails to operate on the Nexus3000 series switches.

Request for Assistance: In light of this issue, I am reaching out for assistance and guidance. I am in need of a switch that supports the "ip default next-hop" command in a manner similar to its functionality on the Catalyst 6509. Specifically, I require a switch where the "ip default next-hop" command within a route-map can replace the default gateway specified in the main routing table. Could someone kindly suggest one or more switches that meet these criteria?

[MHM Cisco World]

Friend 

This second times and I will answer you same 

Use two set ip next verify under PBR

One for next-hop match what you use in RIB (this emulate default) and second is for your need other next-hop 

MHM

[2swat]

Hello. Please provide an example, as I don't fully understand the concept from your words. Thank you!

p.s.

no ip route 0.0.0.0/0 10.10.3.1


route-map PBR-VLAN82 permit 10
  match ip address VLAN82-ACL
  set default ip next-hop 10.10.3.1

route-map PBR-VLAN202 permit 10
  match ip address VLAN202-ACL
  set default ip next-hop 10.10.3.2

interface Vlan82
  ip policy route-map PBR-VLAN82

interface Vlan202
  ip policy route-map PBR-VLAN202

Is this what you're suggesting to do?

[MHM Cisco World]

the 10.0.0.1 is next-hop show in RIB 
the 20.0.0.1 is next-hop you want to force traffic to WHEN the 10.0.0.1 is down

MHM

[2swat]

I understand you. But what I need is not reservation, but static distribution based on incoming networks. For example, this network on gateway 10.10.10.1, another network, let it come from another interface, should go to another gateway, let it be 20.20.20.1.

This can be implemented on Catalyst 6509, using set default next-hop. Without set default next-hop, there will be no redirection, no static redirection without reservation or balancing.

And what's important, set default next-hop checks the local routing table and sends the packet where it should go, rather than immediately sending it to 10.10.10.1. Because the set next-hop command will do just that, without checking the routing table it will send the packet further. And I don't want that.

[MHM Cisco World]

Yes I understand your requirements' this workaround not optimal solution' 

But if 10.0.0.1 is next-hop ALWAYS for route in RIB you can use my workaround' if the next-hop is change then this solution not work.

MHM

[2swat · Accepted solution]

The command set default ip next-hop appears to be non-functional. Even after removing the default route from the main routing table, packets remain trapped within the route-map rules without progressing further. Only 'set ip next-hop' seems to work, which is not satisfactory. It seems likely that this behavior extends to all Nexus equipment. Unfortunately, I lack the means to verify this further, but I have drawn my conclusions.

[balaji.bandi]

some command syntax different compare to IOS and nexus OS and some limitation of using it.

can you post the sample configuration to look what configured and suggest is that really work on nexus :

some reference guide 9K model but should be same as 3K also (near by)

https://www.cisco.com/c/en/us/td/docs/dcn/nx-os/nexus9000/103x/unicast-routing-configuration/cisco-nexus-9000-series-nx-os-unicast-routing-configuration-guide-release-103x/m_configuring_policy-based_routing_101x.html#task_qwc_rpj_swb