[c-nsp] Cisco 7600/SUP720-3BXL SRD -> SRE => Egress -> Ingress Multicast Replication Mode

[Emanuel Popa]

Hi there,

A while ago we upgraded our 7600 Cisco boxes with SUP720-3BXL and LAN
cards from SRD to SRE IOS version. After successfully upgrading all
boxes we noticed at least a strange behavior: all Cisco 7600 boxes had
"mls ip multicast replication-mode ingress" as an extra command in
their running configuration file. Before upgrading, all boxes were
doing egress replication for multicast traffic. And it seems they are
still able to do it:

#show platform software multicast ip capability
Current System HW Replication Mode : Ingress
Auto-detection of Replication Mode : OFF
Slot Replication-Capability Replication-Mode
   1 Egress                 Ingress
   2 Egress                 Ingress
   3 Egress                 Ingress
   4 Egress                 Ingress
   5 Egress                 Ingress
   9 Egress                 Ingress

Any ideas why Cisco would disable auto-detection of replication mode
in new software releases? Or why Cisco would force ingress replication
instead of egress replication for capable boxes?

Regards,
Manu