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Domain ID overlap on port for my MPX110 FCIP's for SAN to SAN replication

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  • 1.  Domain ID overlap on port for my MPX110 FCIP's for SAN to SAN replication

    Posted 07-12-2016 01:24 PM


    I could really use your assistance.

    I am trying to create a lun replication SAN to SAN (on HP EVA 4400 in 2 different states). They are 2 separate fabrics I need to link/merge in to one. Brocade 200 in one location, Brocade 300 in the other location.

    I just configured a MPX110 FCIP switch at each location to create a long ISL link between the 2 SAN's and across states.

    The port on my Brocades for the MPX110 switch is ISL ready however when I plugged in the 2nd MPX on my brocade I saw the following event warning (on both locations brocades): Warning: port 5, domain IDs overlap

    On my SAN side, Data Replication shows "no path"


    Turns out one of the brocades I plugged the MPX switch in to has the same Domain ID as another separate brocade in my environment (not part of this mpx link but on the same fabric as the brocade that is).


    So I'm assuming this Domain ID overlap/conflict is the reason my 2 brocades won't merge in to one fabric, correct?


    If I were to do the following steps, would this immediately correct the issue and my 2 brocades in separate states, connected by MPX110 swich, immediately merge together in to one fabric?

    • GUI - Configure - Switch View - Switch tab - Under Switch Status - Disable.
    • Domain ID field should now be editable - enter new Domain ID #.
    • Switch Status - Enable.


    If that works, how long does it take till I see the merged fabric?

    What happens to the existing zone configurations on both brocades? do they just merge together? Is there a risk of anything getting deleted/blown away?

    Do I have to set the brocade, that has the more extensive zoning configuration I want, to be the Principal Switch? via "Set as preferred Principal Switch".

    Right now, both my brocades that I want to fabric merge, have Switch Role of Principal. Will this cause an issue when I switch enable one brocade?


    thank you for any and all assistance you can provide!




  • 2.  Re: Domain ID overlap on port for my MPX110 FCIP's for SAN to SAN replication

    Posted 07-12-2016 07:29 PM

    From the looks of it it seems you don't have much experience with storage networks. There are many thing that can go wrong if you don't plan your environment. In you case you would indeed need to change the domain ID but that could potentially also render your fabric inoperable if you've used DID/PID zoning. Even if you use PWWN zoning and you've changed the domain ID the fabrics are likely to segment due a zoning difference.


    I don't know the MPXcapabilties but if it supported FC-routing functionality with VEX-ports I would pursue that option.


  • 3.  Re: Domain ID overlap on port for my MPX110 FCIP's for SAN to SAN replication

    Posted 07-13-2016 07:27 AM

    No I do not have much experience with brocade, storage networks which is why I'm asking for assistance on this forum. I did not build the original SAN/Brocade environment. I inherited it and am trying to learn as much as I can and make sure I double check before making big changes.

    I plan to have my lone brocade in the one location have the same exact zone config as the fabric it is going to join in the other location - I am doing this by manually entering any missing aliases, wwn's, zones and zone configs. Both brocades will have exact matching zone configs before I switchdisable, change domain id and switchenable to join and merge into same fabric.


    Insistent Domain ID Mode is disabled on all my brocades.

    We have 2 Brocades in one location (neither part of a fabric)

    We have 6 Brocades on our other separate secondary location - These 6 brocades are broken up in to separate fabrics, say Fabric A and Fabric B - each fabric with 3 brocades (allowing for redundancy).


    We had 1 of the 2 brocades linked via MPX110 FCIP switch to Fabric B in the other location. This merged those 2 locations in to one fabric so we could do SAN to SAN replication. That MPX110 switch broke which broke the fabric link and obvioulsy the zone configs became different (no longer merged).


    I came in and fixed the MPX110 issue so we can now link the 2 locations in to one fabric again as it used to be. Issue is this lone brocade threw the Domain ID overlap error (as it is conflicting with one of the 3 brocades in Fabric B at the secondary location).

    I now have no choice but to switchdisable, change the Domain ID (on this lone brocade), switchenable to have it effectively join the Fabric B (at 2ndary location) again.

    My concern is the lone brocade, when merged, wiping out the existing Fabric B (at 2ndary location) rather then the existing Fabric B overwriting the lone brocade which is what I want. My solution for this is comparing the 2 zone configs and I am ensuring they both match up, adding in any that need to be, before I do the switchdisable. This should take the zone config worry out of the way.

    Is that true? or should I disable the current zone config on the lone brocade, renaming config, before switchenable and having it join the fabric and then selecting "choose zone config to make preferred choice"?


    I hope I explained all that effectively.





  • 4.  Re: Domain ID overlap on port for my MPX110 FCIP's for SAN to SAN replication
    Best Answer

    Posted 07-13-2016 02:15 PM
    When switches are connecting, there's no means that one of the zoning configs will be deleted, blown away and replaced with another zoning config. It just doesn't work this way. You have four scenarios: 1) both switches are clear and do not have any zoning; 2) one switch is clear from zoning and another has some zoning; 3) both switches have matching zoning; 4) zoning is different between the switches. In first three cases the switches happily merge, provided that all other settings (there are many of them) do not conflict. In the last case, the switches stay segmented. That's very much like you've already seen with Domain ID conflict, but the segmentation message will be something like "zoning mismatch". So if you have zoning on both sides, it has to perfectly match when switches connect. And perfectly means: if one switch has a config where zones are listed zone1 zone2 zone3 zone4, and the connecting config lists them zone3 zone4 zone1 zone2 - it is a mismatch. The same applies to zone members and alias members (if you have aliases that include more than just one WWN)

  • 5.  Re: Domain ID overlap on port for my MPX110 FCIP's for SAN to SAN replication

    Posted 07-14-2016 05:48 AM

    Alexey, thank you so much for replying. Your explanation was extremely helpful to me and answered my concerns. Thank you again for that!

    I am in the process of manually matching my 'lone' brocade with the fabric and brocade I plan to merge with (and vice versa). This includes exactly matching all the aliases, zones and zone configs. I don't believe I am missing anything there, correct?

    I have taken backups of both brocades with configupload and supportsave in case.


    Now IF I misspelled an alias say (I like to plan for extremes) and I switchdisable, change domain id, switch enable which should merge the fabrics but does not due the misspelling, the fabrics will not be merged and I will now get a "zone mismatch" on my lone brocade, correct? What is the resolution to that scenario?

    Could I then (in GUI) Switch View - switchdisable - Zone Admin - disable zoning - rename that zoning config - switchenable - "choose preferred zone config to be enabled" and choose the fabric zone I want it to be a part of (my choices should be the newly renamed/old config and the config of the Fabric I want to merge with).



  • 6.  Re: Domain ID overlap on port for my MPX110 FCIP's for SAN to SAN replication

    Posted 07-14-2016 12:40 PM
    > I don't believe I am missing anything there, correct?

    > I will now get a "zone mismatch" on my lone brocade, correct?
    Right. This message will actually show on both sides. They both will keep running with what they had, just say "here I see something that is not good for me"

    > What is the resolution to that scenario?
    I'd get to the config and rename the misspelled name using zoneobjectrename and then bounce the ISL to see that switches will finally safely merge.

    BTW, why do you suspect having a misspelling? I'd script the process, this will make sure no misspellings.

  • 7.  Re: Domain ID overlap on port for my MPX110 FCIP's for SAN to SAN replication

    Posted 07-14-2016 01:14 PM

    Once again, thank you Alexey!

    OK so the command zoneobjectrename would allow me to rename the Defined Configuration (cfg) name on the one brocade or is it just allowing renaming of alias or zone, etc? Would I have to disable Zoning before renaming the config? In the GUI if I go to Zone Admin - Zone Config I see my CFG name and entries. If I click the "rename" button is states "Sorry you cannot rename and enabled Config. Please disable this config before renaming it."'

    If so this would be cfgdisable (or disable zoning in GUI) - zoneObjectRename "brocade_CFG_name", "new_brocade_CFG_name" - then switchdisable/switchenable to pull the existing zone configuration from brocade fabric?

    I apologize for my ignorance, I am trying to learn as much as I can quickly.


    IF I were to get a "zone mismatch" wouldn't it be easier and faster for me to Disable the zone configuration (cfgdisable), rename that zone configuration (in GUI Zone Admin - Zone Config - it is labeled Rename) then either reboot my MPX110 FCIP switch which is the ISL link b/t both brocades or just switchdisable then switchenable?


    I have triple-checked my aliases, WWN's, zones and zone configs and they match, I just worry if another co-worker happened to add an entry (even though I said not to) before I make my changes for this on Sunday. I did not run a script, great idea! so I'll have to find one.

    this is why I asked about if I received a "zone mismatch" after I changed the Domain ID #. I just wanted to definitely know what to do IF that occured.

    I like to have all my avenues covered so I am prepared for any issues that may arise.




  • 8.  Re: Domain ID overlap on port for my MPX110 FCIP's for SAN to SAN replication

    Posted 07-14-2016 03:11 PM
    I'm not sure why you are so concerned about the name of the config. Is it so complex and easy to misspell?

    Zoneobjectrename is to rename zones and aliases names.

    The best way to check if configs match is to do a cfgshow on both sides, copy the output to the text files, and then diff these files. If diff is happy - the configs are matching. If not, it will show you the places where something is wrong.

  • 9.  Re: Domain ID overlap on port for my MPX110 FCIP's for SAN to SAN replication

    Posted 07-15-2016 06:13 AM

    I am not concerned about misspelling configuration file - it was just for any alias or zone misspellings between the 2 brocades. I have gone through and compared all aliases, zones, order of aliases within the zones and the zone config - all matches now.


    Currently both brocades have the same exact config file name. This is where I was questioning IF I had to rename this config file as they are the same before merging fabrics.


    To give background:

    Brocade2 in one state was merged to Fabric B with Brocade 2B in another state. They were connected across states with a MPX110 FCIP switch to ISL ready ports on the brocades. As they were merged they had the same config name, ex: brocade2_CFG_2, with all the same aliases, zone and zone configs.

    About a year ago this MPX110 FCIP switch broke and no one fixed it till me this past Monday. Within that year, as you can imagine Brocade2 had new aliases and zones added to it that were not in sync with Brocade2B and vice versa since they were no longer merged. However both brocades still have the same config file name of brocade2_CFG_2.


    When I fixed the MPX110 FCIP switch this Monday, the Brocade2 could not successfully merge back to Fabric B due a domain ID overlap with another 3rd brocade in that Fabric B (thankfully b/c as I mentioned changes were made on both ends with new aliases, zones - so even though they share the same config file name, the contents are now different).


    I have now made sure all the config contents (aliases, zones, order of aliases within the zones and the zone config) exactly match.

    On Sunday, I have to disable Brocade2 - change the Domain ID # - renable Brocade2 to merge it back in to the Fabric B with Brocade2B that is used to be a part of. Keep in mind both brocades still have the same exact config file name of brocade2_CFG_2. This should not cause a merge issue when I change the Domain ID and re-enable Brocade2 correct?


     I was just trying to be proactive and determine what my next step would be IF I still had a zone mismatch for some reason, even after verifying all zone contents are exactly the same and the config file is the same.





  • 10.  Re: Domain ID overlap on port for my MPX110 FCIP's for SAN to SAN replication

    Posted 07-18-2016 08:04 AM

    Update: Once I changed my Domain ID, my brocade successfully merged in to the Fabric and I was able to initiate SAN to SAN replication. Thank you alexey.stepanov for your assistance and helpful advice!