BGP AS Prepend and Soft In/Out

[johnlloyd_13]

hi,

i have a single site/router with single upstream ISP and i'll be applying AS prepending via a route map.

BGP isn't something i do on a daily basis and just need some advice.

my questions:

1) do i apply the BGP route map in or out?

2) do i perform BGP soft in or out?

route-map AS-PREPEND permit 10
 set as-path prepend 123 123

router bgp 123
 address-family ipv4
 neighbor 200.1.1.1 remote-as 456
 neighbor 200.1.1.1 route-map AS-PREPEND out   <<< DO I USE IN OR OUT?

#clear ip bgp 200.1.1.1 soft in    <<< DO I USE IN OR OUT? OR CAN I JUST USE "soft" THEN HIT ENTER

[Giuseppe Larosa]

Hello @johnlloyd_13 ,

the route-map has to be applied outbound = OUT

At this point you should also clear soft out but you can also perform an hard clear if you want.

Hope to help

Giuseppe

[johnlloyd_13]

thanks!

can i just issue with a 'soft' and it will do both 'in' and 'out'?

#clear ip bgp 200.1.1.1 soft  

[Giuseppe Larosa · Accepted solution]

Hello @johnlloyd_13 ,

if both routers support the route refresh capability you can use the in option without soft keyword

see

https://www.cisco.com/c/en/us/td/docs/ios-xml/ios/iproute_bgp/command/irg-cr-book/bgp-c1.html#wp2094373124

According to the command reference you can also use the soft option alone.

Hope to help

Giuseppe