Add large BGP community to selectively disable prepends #946
Description
IXP manager currently supports the following large BGP communities for prepends:
RS:101:PEERAS - Prepend to PEERAS once
RS:102:PEERAS - Prepend to PEERAS twice
RS:103:PEERAS - Prepend to PEERAS three times
When PEERAS is set to 0, prepeds are applied to all IXP peers.
If ISP sets e.g. RS:101:0, it can still increase number of prepends for some peers with RS:102:PEERAS or RS:103:PEERAS, but can't revert to zero prepends anymore.
I'd therefore propose to introduce new community:
RS:100:PEERAS - Do not prepend to PEERAS
which will solve the above problem and fall nicely into the range reserved for AS Path prepending: RS:100-199:*