Cisco Support Community
Showing results for 
Search instead for 
Did you mean: 

Welcome to Cisco Support Community. We would love to have your feedback.

For an introduction to the new site, click here. And see here for current known issues.

New Member

CISCO 4948 EOAM protocol support

This is a query related to Link layer Ethernet OAM (EFM) support in the WS-C4948E V05. 

The Cisco switch in our lab is being interoperated with a host card having the Ethernet OAM functionality. However, we have certain observations regarding the implementation of the Ethernet OAM (IEEE 802.3ah) in the Cisco switch. Please find the details below

1)     During Discovery our host card is configured in ACTIVE OAM Mode and the Cisco switch in PASSIVE Mode. An Information OAMPDU is sent from our host card to switch. If the bit for support of Link Event interpretation in the OAM configuration field in Local Information TLV is disabled at host card, switch never gets satisfied and Discovery is never successful. However as per the IEEE standard, the link event bit can be enabled or disabled. The discovery with the switch gets completed only on enabling Link Event support. Same observation is there when host card is in PASSIVE mode and switch is in ACTIVE mode. Please suggest the reason for such a behavior by switch.

2)     In the second case Ethernet OAM is enabled on Switch in ACTIVE mode and on the host card in PASSIVE mode. When Loopback is started by Cisco Switch, Loopback Control OAMPDUs and corresponding Information OAMPDUs (with changed states of Parser and Multiplexer) are correctly exchanged between switch and our host card. However, the test frames are not initiated from the Cisco switch after the control PDUs for loopback are successfully exchanged. What kind of test frames are sent by switch? What is the payload and header content in it? Also what are the commands to check the Loopback statistics in the switch?

Requesting an early reply from the knowledgeable community.