Missing BGP Topology Details in BGP domain manager

Products

• VMware Smart Assurance
• Network Observability

Issue/Introduction

Symptoms:

• The BGP domain in the Domain Manager console appears to missing significant topology details (BGPSessions, BGPProtocolEndpoint ..etc) compared to the source environment.
• BGP-specific components are not being discovered or populated despite the domain being active.

Environment

All Supported Smarts releases

Cause

Check if the server is configured to disallow traffic on port 161 which may lead to discovery failures on the BGP domain manager.

Unfortunately, the BG domain may not log all the SNMP probe failures, hence the best way to check this is via a SNMPWalk from the <NPM>/smarts/bin directory:
Sample errors observed on SNMPWalk as follows:

/NPM/smarts/bin# sudo ./sm_snmp -d #.#.#.# -p 161 --snmp=2c -c <community> walk .1.3.6.1.2.1.15.2
SNMP Walk MIB starting at .1.3.6.1.2.1.15.2
[Date & Time] t@<epoch> <Primary Thread>
SNMP-E-ESENDTO-Cannot send data to #.#.#.#:161
 <SYS>-EPERM-Operation not permitted
 NX-SENDTO-Unable to send message of 45 bytes to destination #.#.#.#:161.; in file "/work/redcurrent/DMT-10.1.9.0/19/smarts/clsapi/network/lib/NX_Socket.c" at line 259

Resolution

Please review the following with your Linux Administration Team 

•  Review using the following command if port 161 is allowed in the UDP port configuration: 
  
  Command: nft list ruleset
  Example Output section to review for UDP configuraiton:

set allowed_udp_dports {
                type inet_service
                elements = { 53, 88, 123, 389, 464 }

• If you are presented with similar configuration where the port 161 is missing; You would need to add the port 161 to this list and restarted the nftables service. 
  Alternate way to update this list includes the command:

nft add element inet filter allowed_udp_dports { 161 }

• Evaluate if the following command returns any drops on INPUT or OUTPUT configuration:
  Command: iptables -L

Note: All the above changes are Server level changes and not related to Broadcom Smarts product. Hence, please engage with your internal team for configuration review and allow traffic over the SNMP ports (on the server and over the network) accordingly.