Everflow mirror session is not active if the mirror destination is in remote asic & monitor_port is not always Ethernet-Rec port

[saksarav-nokia]

Description

1. If the destination IP of the everflow mirror is in the remote asic in the chassis, orchagent never activates the mirror. When the nexthop is resolved, it calls the function updatenextHop->updateSession->getNeighborInfo. In getNeighborInfo function, it takes the nexthop and compares the ip address and alias of nexthop with neighbor entry. But for remote nexthops, the alias stored in nexthop table is the name of Inb port, but the alias in the neighbor entry is full system port. So the alias check always fails and hence the getNeighborInfo always returns false and the mirror is not activated.

2)In orchagent mirror code function activateSession , the MONITOR_PORT is set to Rec port if the switch_type is voq. But in the function updateSessionDstPort, the switch_type is not checked and the MONITOR_PORT is set to destport of nexthop.

Steps to reproduce the issue:

1. configure the ERSPAN mirror with destip pointing to remote asic.
2. configure the ingress Acl with the ERSPAN mirror as Acl action.
   3.Check "show mirror-session" output

Describe the results you received:

mirror session is in inactive state

Describe the results you expected:

Mirror should be activated and the monitor port configured for ERSPAN mirror is always Rec port.

Output of show version:

msft-2205 & master

(paste your output here)

Output of show techsupport:

(paste your output here or download and attach the file here )

Additional information you deem important (e.g. issue happens only occasionally):

[saksarav-nokia]

One more issue with mirror code for ERSPAN mirror in voq chassis. When the mirror is created, the SAI_MIRROR_SESSION_ATTR_DST_MAC_ADDRESS is set to gMacAddress.getMac() if it is voq chassis. But In function updateSessionDstMac, this code is missing and the SAI_MIRROR_SESSION_ATTR_DST_MAC_ADDRESS is set to next_hop's mac and hence the mirrored ingressing on recycle port is not routed.

[zhangyanzhao]

Is this issue handled by #2392? @saksarav-nokia

[saksarav-nokia]

@zhangyanzhao , yes. I have few more changes and i will update the PR by end of this week

[saksarav-nokia]

Found few more issues with Everflow mirror

1. show mirror-session doesn't show correct monitor port when the destination port is in remote asic
2. When the Acl rule with action as mirror is deleted before mirror is activated by the acl_loader script, then mirror is activated by nexthop update, lot of error messages were seen and orchagent crashes.

[abdosi]

should be fix by: sonic-net/sonic-swss#2392

[abdosi]

There is another PR on everflow: sonic-net/sonic-swss#2024