On 2011-04-26 01:11, Martin T wrote:
When Cisco switch or router port is "connected", it has status "line protocol is up". As far as I know, this applies to all interface types(10BASE-T, 100BASE-TX, 1000BASE-T, 1000BASE-LX10, 1000BASE-SX etc with different transceivers). What is this "line protocol"? I always thought "line protocol" is up once any electrical pulses are detected by Rx. Or is "line protocol" strictly "link integrity test"(LIT) pulses(100-200ns of electrical pulses with 16ms+/-8ms interval)? Any clarification would be much appreciated.
"Line protocol" for Ethernet interfaces is Ethernet frame. Cisco boxes send Ethernet keepalive frame and when it doesn't loop back, they declare line protocol down: http://www.cisco.com/en/US/docs/ios/12_3/interface/command/reference/int_i1g.html#wp1154231 -- "There's no sense in being precise when | Łukasz Bromirski you don't know what you're talking | jid:[email protected] about." John von Neumann | http://lukasz.bromirski.net _______________________________________________ cisco-nsp mailing list [email protected] https://puck.nether.net/mailman/listinfo/cisco-nsp archive at http://puck.nether.net/pipermail/cisco-nsp/
