BGP Question FortiGate 7.4

[BillMac]

Does FortiGate BGP support the use of both 16 and 32 bit AS numbers? I've been looking at the FortiGate 7.4.2 admin guide and not seeing anything definite there to answer my question.

Bill

[Toshi_Esumi]

Both are working in our 7.0.x/7.2.x environment.

Toshi

xxxxx # get router info bgp sum

VRF 0 BGP router identifier x.x.x.x, local AS number 65528
BGP table version is 23499
1021 BGP AS-PATH entries
436 BGP community entries

Neighbor V AS MsgRcvd MsgSent TblVer InQ OutQ Up/Down State/PfxRcd
10.x.x.x1 4 4290241234           0           0         0 0 0 never Active
10.x.x.x2 4 4290009091 249435 273041 23499 0 0 01w0d04h 0
10.x.x.x3 4 4290009090 249849 273232 23499 0 0 01w0d04h 2
10.x.x.x4 4           64522           0   41614          0 0 0 never Active
69.x.x.x   4           3xxxx 327241 249880 20174 0 0 07w1d14h 54
<snip>

Total number of neighbors X

[BillMac]

Thank you for the response.

Cheers

[ashishrathee · Accepted solution]

Yes, FortiGate units support both 16-bit and 32-bit AS numbers for BGP.  AS numbers are 4 bytes long instead of the former 2 bytes. RFC 4893 introduced 32-bit ASNs, which FortiGate units support for BGP and OSPF. This means you can use both 16-bit and 32-bit AS numbers with FortiGate BGP configurations.

[BillMac]

Thank you.

Cheers

[mpapisetty]

Just FYI, this has been in support for a long time on the Fortigate. The 5.6 handbook talks about it - https://fortinetweb.s3.amazonaws.com/docs.fortinet.com/v2/attachments/cf390652-1a11-11e9-9685-f8bc12...

"NAs of January 2010, AS numbers are 4 bytes long, instead of the former 2 bytes.
RFC 4893 introduced 32-bit ASNs, which FortiGate units support for BGP and OSPF."