I'm venting a bit here but, I had major beef with the PG solution on this task.
They didn't even address the requirement, unless I am missing something here.
Task-
"BGP AS 178 has two equal paths to AS 111 via R5 and R6. Configure R7 so R6 is
the PRIMARY route for ALL ROUTES ORIGINATING FROM AS 111 and a BACKUP FOR ALL
OTHER ROUTES.
R5 should be the BACKUP FOR for ALL ROUTES ORIGINATING FROM AS 111 and the
PRIMARY route for ALL OTHERS."
The PG Solution was-
ON R7 CONFIGURE:
router bgp 178
no synchronization
bgp log-neighbor-changes
neighbor 110.99.6.6 route-map lp in
route-map lp permit 10
set local-preference 200
....So how does that address the requirement?
Shouldn't the configuration address the ASpath requirement? The PG solution is
simply modifing local pref on ALL routes, which is not what was asked for
PLUS those routes that would be coming in .... the Aggregate we configured on
R5 and R6 originate in AS112! which should take the path to R5 !
Even the output in the PG solution guide is incorrect, it shows 172.16.0.0/21
going to R6.
Shouldn't the configuration be:
ON R7 CONFIGURE:
router bgp 178
neighbor 110.99.5.5 route-map BACKUP_R5_AS111 in
neighbor 110.99.6.6 route-map PREFER_R6_AS111 in
ip as-path access-list 1 permit ^_111$
route-map BACKUP_R5_AS111 permit 10
match as-path 1
set local-preference 100
route-map BACKUP_R5_AS111 permit 20
set local-preference 200
!
route-map PREFER_R6_AS111 permit 10
match as-path 1
set local-preference 200
route-map PREFER_R6_AS111 permit 20
set local-preference 100
