When a sonet interface is made admin down, the oper status remains up. It is because the oper status depends on the RX link of the interface. Please check the below log.

user@host> show interfaces terse so-1/0/0
Interface Admin Link Proto Local Remote
so-1/0/0 up down
user@host>


The SNMP trap that I get for the above state is
SNMP_TRAP_LINK_DOWN: ifIndex 532, ifAdminStatus down(2), ifOperStatus down(2), ifName so-1/0/0

I feel the ifOperStatus should be shown as up in the SNMP TRAP. but I was told by the developer that, as per the RFC 1573, when interface is admin down then oper status should also go down. (please refer the below rfc snippet).

RFC says that when an interface is admin down, oper status will also go down in some time. I feel this statement will hold good for gigethernet interface but not for sonet interface. because sonet interface oper status will not go down in sometime. because it depends on the rx of the interface. Please tell me what should be the correct SNMP TRAP raised?



Snippet from RFC 1573, Section: 3.2.12:
Note that when ifAdminStatus transitions to down, ifOperStatus will
normally also transition to down. In this situation, it is possible
that ifOperStatus's transition will not occur immediately, but rather
after a small time lag to complete certain operations before going
"down"; for example, it might need to finish transmitting a packet.
If a manager station finds that ifAdminStatus is down and
ifOperStatus is not down for a particular interface, the manager
station should wait a short while and check again. If the condition
still exists only then should it raise an error indication.
Naturally, it should also ensure that ifLastChange has not changed
during this interval.

The admin down means that the interface is forced to bring down. That means that ifOperStatus should be down.
The text you mentioned means that a error indication should be on if ifOperStatus isn't same as ifAdiminStatus. On other words, ifOperStatus should be down if ifAdminStatus is down.

Hi nini09,

Thanks for your reply.

Yes if admin status is down then oper should also be down in ethernet interface. is it same for sonet interface as well?
sonet interface oper status is not based on the rx of its interface? Below is the comment that I got from software team for the sonet interface behavior.

"This behavior is expected as in sonet 'oper' status depends on Rx link of that interface. S/W does not forcefully make the oper status down on disabling a sonet interface"

Yes, SONET network should follow the rule.