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Occasional Contributor
Posts: 18
Registered: ‎12-10-2009

Why E-port does not have "downstream" status?

Hi,

I have Brocade 3850 switch with two E-ports. This switch is principal, so both E-ports must be "downsream", but only one E-port has "downstream" status - other has no status at all.

Look at the "switchshow" output:

14  14   id    N2   Online           E-Port  10:00:00:05:1e:b4:87:0f "IBM_2498_B24_1"
15  15   id    N2   Online           E-Port  10:00:00:05:1e:03:03:6d "IBM_2005_B16_1" (downstream)

Could anybody explain, why port no. 14 does not have "downstream" status? All 3 switches are interconnected as "ring".

Thanks.

BR,

Danas Kazlauskas

Super Contributor
Posts: 644
Registered: ‎03-01-2007

Re: Why E-port does not have "downstream" status?

--->>> I have Brocade 3850 switch with two E-ports.

--->>> 14  14   id    N2   Online           E-Port  10:00:00:05:1e:b4:87:0f "IBM_2498_B24_1

2498-B24 is the Genuine Brocade 300

when you create a simple ISL ( not ISL Trunking ) in this case the switch with the lowest WWN "b4:87:0f" become as upstream also Principal, all other switch are in downstream.

The goal  by dual ISL is so that if one switch goes offline or whatever  then the other switch takes over. There is no need to configure any second or more port.

To avid compatibility problem, make sure you have compatible FOS Release, beetwen the Fabric.

Occasional Contributor
Posts: 18
Registered: ‎12-10-2009

Re: Why E-port does not have "downstream" status?

All switches FOSes are compatible - I already has checked that.

No trunking - every switch is connected to other switch ("ring" or simple 3-switch "mesh" configuration).

Danas

Super Contributor
Posts: 644
Registered: ‎03-01-2007

Re: Why E-port does not have "downstream" status?

I cannot see from here you Fabric or you config, or if all switch are correct configured.

if you need more help, collect "switchshow" all 3 switches, let us the exact FOS release is installed, collect with command "fabricshow" the o/p,

Occasional Contributor
Posts: 18
Registered: ‎12-10-2009

Re: Why E-port does not have "downstream" status?

Hi,

outputs from "switchshow" and "fabricshow" are in Putty log attached below.

Thanks.

Danas

Super Contributor
Posts: 260
Registered: ‎04-09-2008

Re: Why E-port does not have "downstream" status?

If I remember correctly, such a mismatch is observed when you replace SFP or cable on one of the ISL ports.

Try to disable/enable one of the ports if possible, this action could be disruptive hence please take proper care.

New Contributor
Posts: 3
Registered: ‎06-18-2009

Re: Why E-port does not have "downstream" status?

If both ports are connected to the same destination switch, then only one port shows as "downstream", but the others will handle traffic.

Occasional Contributor
Posts: 18
Registered: ‎12-10-2009

Re: Why E-port does not have "downstream" status?

As I remember, I already has tried to disable/enable these ports, but situation has not changed.

BR,

Danas

N/A
Posts: 1
Registered: ‎03-03-2010

Re: Why E-port does not have "downstream" status?

Dear Danas,

This is a cosmetic thing which has nothing to do with data traffic or frames being sent over the ISLs.

If you look at your fabric which consists our of 3 switches in a ring.

and have a look at fabricshow output

Switch ID   Worldwide Name           Enet IP Addr    FC IP Addr      Name
-------------------------------------------------------------------------
  1: fffc01 10:00:00:05:1e:34:ec:2c 10.69.0.138     0.0.0.0        >"IBM_2005_H16_1"
  2: fffc02 10:00:00:05:1e:03:03:6d 10.69.0.134     0.0.0.0         "IBM_2005_B16_1"
  3: fffc03 10:00:00:05:1e:b4:87:0f 10.69.0.153     0.0.0.0         "IBM_2498_B24_1"

I'll rap up the names to H16, B16 and B24 to keep it simple.

H16 is principal

B16 is subordinate to H16

B24 is subordinate to H16 and B16

Looking on H16, this switch will show the ISL connected to it's subordinate switch B16 as being "downstream"

Looking on B16, this switch will show the ISL connected to H16 as being "upstream"

                        it will also show the ISL connected to B24 as being "downstream"

Looking on B24, this switch will show the ISL connected to B16 as being "upstream" again

                        Now here is the tricky part, since the ISL connected to H16 would imply being a DOWNSTREAM connection

                        And when looking from H16 you would expect the ISL connected to B24 should be DOWNSTREAM as well since the B24 is subordinate to H16, this is were it drops the announcement whether the link is upstream of downstream.

This also applies only to the first ISL that came online between any of the two connected switches, any additional ISLs will never show whether it's upstream or downstream not even when you trunk multiple ISLs.

This was an almost prehistoric cosmetic way to determine topology of the fabric, but has been replaced by all those fancy GUI based management tools we all like to use...

Hope this explains your question... so don't worry and surely don't reset the ISL ports ;-)

Cheers, Wim.

Occasional Contributor
Posts: 18
Registered: ‎12-10-2009

Re: Why E-port does not have "downstream" status?

Many thanks, Wim!

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