route tag command on interface

[carl_townshend]

Hi Guys

I saw an ISP router interface the other day with a route tag applied to the interface

ipv4 address 192.168.1.1 255.255.255.0 route-tag 5 command

Would this have been a Cisco router? if so what IOS?  I've never seen this command before on an interface, Would it tag any routes going to any of the routing protocols with that tag?

Cheers

[MHM Cisco World]

If you can run sdwan lab

Check this command in vedge router 

I think you can apply it ubder vpn0 

MHM

[Jens Albrecht]

Hello @carl_townshend,

I have never seen this kind of syntax used on any Cisco operating system or other major brands like Juniper or HPE Aruba.

The purpose should be matching and filtering networks for redistribution and the like as you mentioned.

HTH!

[wajidhassan · Accepted solution]

Hi @carl_townshend ,

The route-tag command on an interface is supported on certain Cisco IOS versions, primarily in service provider or advanced IOS images. It applies a tag to routes learned or advertised via that interface, often used in BGP or redistribution scenarios to identify routes.

Not all IOS versions support this on interface configuration, so it may be seen on ISP-grade routers with specific feature sets.

This tag can be used in route-maps or policies to control route advertisement or filtering across routing protocols.

Hope this clarifies.

[bigevilbeard]

Guessing this was IOS XR per https://www.cisco.com/c/en/us/td/docs/routers/xr12000/software/xr12k_r4-3/addr_serv/command/reference/b_ipaddr_cr43xr12k/b_ipaddr_cr42xr12k_chapter_01000.html

HTH