[j-nsp] Limit on the number of BGP communities a route can be tagged with?

[Olivier Benghozi]

And about a limitation to 10 communities:
I've seen that on SEOS (Redback/Ericsson OS for SmartEdge routers) when using "set community" in a route-map. This is a ridiculous arbitrary limitation, of course.

Hopefully the limitation was only in the CLI, not in the BGP code itself. So the workaround was to use the route-map "continue" command like in a BASIC GOTO structure to add more communities in additional route-map entries (with set community additive - these are Cisco-like commands).

> Le 23 août 2016 à 14:03, Alexander Arseniev <arseniev at btinternet.com> a écrit :
> 
> In BGP messages, a regular community is encoded in 7 bytes, and extended one in 11 bytes.
> 
> Max BGP message size is 4096 bytes - this sets a limit for regular communities number to about 4K/7=570, and for extended communities to about 4K/11=360, if You consider the minimal mandatory information that has to be there apart from communities.
> 
> 
> On 23/08/2016 03:18, Huan Pham wrote:
>> 
>> I remember hitting a limit on a number of communities (something like 10 or
>> so) on a platform (can not remember which one from which vendor). So I
>> believe that there is a hard limit a platform or OS can support.
>> 
>> I test this in the lab and found no problem with tagging 100 communities.
>> 
>> Is there a maximum number of communities that Junos can tag to a route? If
>> yes, then what it is?  Thanks.