Technical Tip: 'BGP won't exchange routes after a reboot'

[jcovarrubias]

Description	This article describes an issue where FortiGate fails to share BGP routes after a device reboot due to an improperly configured connect-timer value.
Scope	FortiGate and FortiManager v7.4.6/v7.4.7 and ADOM v7.4.
Solution	Problem Overview BGP sessions may fail to establish when a FortiGate is rebooted, and routes will not be shared. This occurs because the BGP connect-timer is set to its maximum value (65535), causing the FortiGate to wait over 18 hours before attempting to establish a BGP connection. Troubleshooting Steps: Check BGP neighbor status. The BGP summary shows neighbors in the 'Active' state in ADVPN spoke. get router info bgp summary VRF 0 BGP router identifier 4.4.4.4, local AS number 65000 BGP table version is 1 1 BGP AS-PATH entries 0 BGP community entries Neighbor V         AS MsgRcvd MsgSent   TblVer  InQ OutQ Up/Down  State/PfxRcd 10.4.9.2 4      65000       0       0        1    0    0 00:02:07        Active Analyze network traffic: Running packet capture on TCP port 179 (BGP) shows no BGP traffic between devices, suggesting that FortiGate is not attempting to initiate BGP connections. FW#  diagnose sniffer packet any '10.4.9.2 and tcp and port 179' 4 10 Configuration Review: config router bgp   set as 65000     set router-id 9.9.9.9     config neighbor     edit "10.4.9.1"     set remote-as 65000     set connect-timer 65535  <-----    next end Explanation: The issue can be seen when using FortiManager's BGP provisioning templates in v7.4.6 and 7v.4.7. When creating BGP templates, an invalid default connect-timer value is initially set. While FortiManager validates this and allows correction, the value typically defaults to 65535 seconds. This excessive delay prevents BGP connections from establishing in a reasonable timeframe.