[c-nsp] BGP Peer Group drawbacks???

[Phil Mayers]

> and # of prefix's etc...I guess a question could be - why wouldn't you use
> templates - even for a simple BGP config?  Any ISP ops on the list - do you
> use templates, peer-groups - or both?

We use templates, including inheritance. They're very handy.

 From memory however, some things don't quite work with them - the only 
specific example I can think of is using a "bgp listen" e.g. on a 
route-reflector, which will allow any BGP router from a particular 
subnet range to connect. IIRC on 12.2SX, when I tried it, it didn't 
support templates, just peer-groups.

We see some oddities with VPNv4 AFs too; the send-community commands 
seem to not get inherited, but are automatically added to the neighbour 
statements, and soft-reconfig refuses to apply, but AFAICT these are 
cosmetic.

That said, we use a peer-group in one or two places where the config is 
very simple and confined to one router (anycast DNS via eBGP, specifically)

I would use templates in a new deployment, and recommend against 
peer-groups - Marko's email has an excellent summary of the background.