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  • 1.  Aruba 6100 DHCP Not Assigning Addresses Between Two Sites

    Posted Jan 07, 2025 07:57 AM

    We have two sites connected via dark fiber. I'm unable to get DHCP addresses at the new facility. Everything else works fine through if I statically assign an IP so it appears there is something wrong in the port\trunk configs. I'm more of a cisco guy, so I could be missing something obvious here, hoping you can help me out.

    The HP 3810M is at the old site( Site A), the 6300 is at the new site. The two switches are pretty different in terms of CLI language so that's not helping me out any.

    Can you take a look at what I've got configured below and let me know what I'm missing. I've tried many different variations, which all lead back to the same thing. The config below is currently working though IP addresses, but unable to get DHCP addresses. All the scopes are set up in DHCP and subnet has been added in AD Sites and Services. I think my issues lies with the switch config and not passing the proper VLAN IDs.

    Site A (HP Aruba 3810M)

    Int 15

    Untagged VLAN 1002

    Tagged VLAN 2,101

    Site A (HP Aruba 3810M)

    VLAN 1002

    Untagged 15

    Ip address 10.254.254.9/30

    Site A (HP Aruba 3810M)

    Ip route 10.18.0.0/16 10.254.254.10

    Site B (HP Aruba 6300M)

    Int 1/1/16

    Vlan trunk native 1002

    Vlan trunk allowed all

    VLAN 1002

    Ip address 10.254.254.10/30

    Ip route 0.0.0.0 0.0.0.0 10.254.254.9

    Connected IDF switches are all connected with the following configs on both ends

    Native trunk vlan 1

    Vlan trunk allowed all

    Example VLANs on trunked IDF switches (unable to get DHCP from this VLAN, but static IP does work)

    Ip address 10.18.2.1/24 (VLAN 2)

    Ip helper-address 10.17.100.7



  • 2.  RE: Aruba 6100 DHCP Not Assigning Addresses Between Two Sites

    Posted Jan 07, 2025 08:56 AM

    If static IP works fine, but DHCP in the same VLAN doesn't, could it be that you have dhcp-snooping configured on one or more switches? dhcp-snooping not just looks at the traffic, but also blocks dhcp responses from unauthorized servers/interfaces.



    ------------------------------
    Herman Robers
    ------------------------
    If you have urgent issues, always contact your HPE Aruba Networking partner, distributor, or Aruba TAC Support. Check https://www.arubanetworks.com/support-services/contact-support/ for how to contact HPE Aruba Networking TAC. Any opinions expressed here are solely my own and not necessarily that of Hewlett Packard Enterprise or HPE Aruba Networking.

    In case your problem is solved, please invest the time to post a follow-up with the information on how you solved it. Others can benefit from that.
    ------------------------------



  • 3.  RE: Aruba 6100 DHCP Not Assigning Addresses Between Two Sites

    Posted Jan 08, 2025 11:41 AM

    Hello Herman,

    I opened a ticket with Aruba support on this. Their scheduled to call me tomorrow but if you have any other suggestions, I'm open to try anything to get this to work. Thanks for all your assistance so far!

    Thank you!




  • 4.  RE: Aruba 6100 DHCP Not Assigning Addresses Between Two Sites

    Posted Jan 07, 2025 11:35 AM

    Just a note. "Vlan trunk allowed all" really just mean the VLANs that are created on the switches not all possible IDs.

    As Herman mentioned, you might need to check your dhcp snooping.

    Also check the routing of the switch doing the DHCP relay, it has to be able to contact the DHCP server.

    If static IP works, I suppose your VLAN tagging is OK.

    It is a bit hard to tell or pinpoint from that info your provided.

    Do you have a network diagram to add to the thread ?




  • 5.  RE: Aruba 6100 DHCP Not Assigning Addresses Between Two Sites

    Posted Jan 07, 2025 11:40 AM

    Hello, thanks for the replies (both you and Herman). We have confirmed that DHCP snooping is disabled, I'll see what I can do about providing a network diagram. Shouldn't take long to get one together to post to this thread. Thank you!




  • 6.  RE: Aruba 6100 DHCP Not Assigning Addresses Between Two Sites

    Posted Jan 07, 2025 01:28 PM

    Hello R0h0LM and Herman,

    Unfortunately, I don't have a network diagram yet since this site is so new but I do have the following info:

    Site B is the remote site. The two switches that are directly connected via fiber are the 6300 and the 3810. 

    The 6100 is the access switch at site B that I'm trying to pull DHCP on VLAN 2. 6100 int 1/1/49 connects to 6300 int 1/1/1.

    6300 connects int 1/1/16 to 3818 int 15 via vlan 1002. 

     

    6100 iproute 0.0.0.0 0.0.0.0 10.18.101.1

    6300 ip route 0.0.0.0 0.0.0.0 10.254.254.9

    3810 ip route 10.18.0.0 255.255.0.0 10.254.254.10

    We can ping our dhcp servers from the switch(s) via hostname and ip address.

    I've uploaded some files showing our different interfaces and vlan info. 

    Thank you,

    Matthew Poulton


    Attachment(s)

    txt
    Site A 3810.txt   9 KB 1 version
    txt
    Site B 6300.txt   4 KB 1 version