PLOGI messages

[Peter O'Connor]

Guys, periodically and very randomly we get PLOGI messages on our switches (Brocade 2800 - f/w 2.6.0c) from our controllers.. HSG80's.

No FLOGI before hand.. just a simple PLOGI.. mostly overnight or weekends,

any ideas?

[Vincent Fleming]

Well... PLOGI is used for establishing or closing connections between FC devices. This includes connections to the nameserver, etc. within the SAN.

What you are seeing sounds like it's normal. The controllers are probably doing something harmless, such as contacting the nameserver in the switch.

Are there any events that coincide with the PLOGI events? For example, a host on the SAN rebooting...

Is it causing problems? Or are you just concerned with the messages?

[Peter O'Connor]

Thanks for the reply and no it's not causing a problem and no it does'nt corrolate with any other event on our SAN.

We also suspect that it's always happened, (we've only recently enabled monitoring on our switches).

Concern always stems from what we don't understand, so just trying to understand whay things happen the way they do.

Thanks again.

[Oscar_32]

I've seen this same symptom at a customer site who is using A5151A HBAs in their HPUX servers,logged into the switch as F-Ports, going through a 2800. Looking at a Finisar Fibre Channel trace, the PLOGI events (proceeded by LOGO) show up as often as every thirty second and intermittently during heavy traffic, (less often on the switch). When the PLOGI occurs the frame size is set to 960. Aside from the HBAs, other components perform an initial FLOGI followed by a PLOGI with a frame of size = 2048. However, they do not generate any additonal PLOGI. This customer has been struggling with SAN backups and these events are very suspicios. Why the constant LOGO/PLOGI and why a framesize of 960?