[c-nsp] ebgp vs ibgp admin distance

[Michael Nicks]

It all depends on how your routing is structured. My personal belief is 
to carry only loopbacks and p-t-ps (for ebgp nexthop) in ospf area 0. 
All customer routes carried via iBGP, internal-usage routes (NOC, etc) 
carried via iBGP, transitive routes carried via iBGP. I then just LP 
customer vs transitive vs peer vs internal. </personal opinion> :)

Best Regards,
-Michael

-- 
Michael Nicks
Network Engineer
KanREN
e: mtnicks at kanren.net
o: +1-785-856-9800 x221
m: +1-913-378-6516

Shakeel Ahmad wrote:
> in Philip words:
> 
> "
> 
> The default distance for eBGP is 20, the default distance for iBGP is 200,
> and the default distance for OSPF is 110. This means that there is a
> potential for a prefix learned by eBGP to override the identical prefix
> carried by OSPF. Recall from the Routing presentation that there is a
> distinct separation between BGP and OSPF processes – prefixes present in
> OSPF will never be found in BGP, and vice-versa. To protect against
> accidents**, the eBGP distance is set to 200 also.
> 
> 
> ** There have been several incidents in the past where denial of service
> attacks on ISP networks have been successful because ISPs have omitted basic
> routing protocol security. Setting the BGP distances to be greater than any
> IGP is one of the mitigation methods available."
> 
> 
> 
> regards,
> 
> Shakeel