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Cisco Bug: CSCvu94262 - VDOC : CMTS assigns wrong wideband interface on different mac-domain

Last Modified

Sep 22, 2020

Products (1)

  • Cisco cBR Series Converged Broadband Routers

Known Affected Releases

16.12.1

Description (partial)

Symptom:
The cBR8 may assign a wrong wideband interface for VDOC (belonging to a different mac-domain) upon reception of an IGMP join coming from a modem.

This has the effect of causing some tracebacks on the CMTS such as: 

-Traceback= 1#18c0e3f192d271b4c16531849e45d501  :56425A30A000+D548B84 :56425A30A000+D1DE891 :56425A30A000+D573D75 :56425A30A000+D5348B5 :56425A30A000+D5373C8 :56425A30A000+D536771 :56425A30A000+9552CEC :56425A30A000+952DD4B :56425A30A000+952D076 :56425A30A000+95333DB :56425A30A000+952B45A

If enabling debugs (debug cable multicast all/ debug cable multicast forwarding), we can observe the following:

Jul  9 07:50:30.701: cmts_mcast_et_find_cm_exist_sec_intf:find existing bonding secondary intf Wideband-Cable6/0/0:63 for CM aaaa.aaaa.aaaa, group 232.4.4.66, source N/A, but not in cm_rcc 25.something maybe wrong!
-Traceback= 1#18c0e3f192d271b4c16531849e45d501  :56425A30A000+D548B84 :56425A30A000+D1DE891 :56425A30A000+D573D75 :56425A30A000+D51E9B9 :56425A30A000+D51DFFC :56425A30A000+D51DACF :56425A30A000+952E529 :56425A30A000+952D076 :56425A30A000+95333DB :56425A30A000+952B45A

cbr8#show cable multicast db  aaaa.aaaa.aaaa

Session (S,G) : (*,232.4.4.66)
Fwd Intfc    Sub Intfc            Host Intfc      Hosts      Proxy    Static   DCC
Wi6/0/0:63   Bundle1.1            Cable6/0/1          1          N         N     N

cbr8#scm aaaa.aaaa.aaaa wi ch
MAC Address    IP Address      I/F           MAC               DSxUS Primary
                                             State                   WB
aaaa.aaaa.aaaa 172.54.0.9      C6/0/1/UB     w-online(pt)      33x1  Wi6/0/1:4

interface Wi6/0/0:63 assigned, but modem belongs to Wi6/0/1 (different mac-domain), hence incorrect.

Conditions:
On 16.12.1z running with VDOC (cable bonding-group-secondary)
16.12.1y does NOT appear to be affected
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