How do I assign a DHCP address to the VLAN 1 interface on Netvanta 1234?

[Anonymous]

I recently set up a small network for a customer. The network consists of a Netvanta 3120 fixed port access router connected to a DSL modem in bridge mode and a Netvanta 1234 switch. The VLAN 1 interface on the 3120 is at the default IP address of 10.10.10.1. I would like to configure the VLAN 1 interface on the 1234 to request. AOS versions are:

Netvanta 3120 - 18.03.01.00.E

Netvanta 1234 - 18.01.01.00

I set up the DHCP server in the 3120 to recognize the MAC address of the Netvanta 1234 and assign it IP address 10.10.10.2. I configured the VLAN 1 interface on the 1234 to used DHCP to get an IP address. I booted the 1234 and expected to be able to connect to it at 10.10.10.2. When it did not connect, I checked the DHCP bindings on the 3120 and found the Netvanta 1234 had been assigned an address of 10.10.10.3.

I noticed that the MAC address listed on the 3120 for the 1234 was not the same as the MAC address assigned to the VLAN 1 interface. Instead of containing six (6) sets of values, it contained ten (10) sets. It looked as if the Netvanta 1234 added 00:00 to the beginning of the MAC address and 00:01 to the end of the MAC address. If I try to enter a MAC address with ten values

RTR# (config-dhcp...) hardware 00:00:aa:de:0f:80:a0:dd:00:01

the router will not access the address. It reports that it is invalid.

I tried to set up the VLAN 1 interfaces for the single switch on this small network as a test for a much larger network that I am designing. On the larger network, I would like to use DHCP to assign addresses to VLAN interfaces on Netvanta 1544F L3 switches. Either the VLAN DHCP function does not work in the 1234 or I there is something that I do not understand. Has anyone successfully configured DHCP to assign IP addresses to VLAN interfaces?

[Anonymous]

- Thank you for asking your question on the forum. The hardware address you should use in configuring the DHCP host reservation for the VLAN interface of the 1234 can be found by issuing the "show interface vlan 1" command. Instructions on how to configure this exactly can be found in the following thread: DHCP Pool Creation .

I am not aware of any issues with the 1234 obtaining a DHCP IP address on its VLAN interface. I did want to ask where you viewed the MAC address of the NetVanta 1234 on the NetVanta 3120 where you saw ten sets?  If you obtained this from the DHCP server bindings, keep in mind that the DHCP client identifier includes the hardware type as well as the MAC address of the client. If you are still having issues configuring this to work, it would be helpful to see the following:

1. Output to "show interface vlan 1" on the 1234

2. The DHCP configuration on the 3120

3. Output to "debug ip dhcp-server" from the 3120

Thanks,

Noor

[Anonymous]

This info is from a Netvanta router. If multiple VLANs on the same L3 switch or router have the same MAC address, is it possible to use DHCP to assign addresses to each VLAN?

HHDTRTR01>show int vlan 1

vlan 1 is UP

  Hardware address is 00:A0:C8:5A:D3:B1

  vlan 1 Ip address is 10.10.10.1, netmask is 255.255.255.0

  MTU is 1500 bytes, BW is 100000 Kbit

  ARP type: ARPA; ARP timeout is 20 minutes

  Last clearing of "show interface" counters: 2d 05:37:45

  5 minute input rate 5208 bits/sec, 8 packets/sec

  5 minute output rate 6312 bits/sec, 10 packets/sec

    1903846 packets input, 140498967 bytes

    1902271 unicasts, 1575 broadcasts, 0 multicasts input

    2132348 packets output, 162162435 bytes

    2132344 unicasts, 4 broadcasts, 0 multicasts output

    0 discards

HHDTRTR01>show int vlan 5

vlan 5 is UP

  Description: Heron Harbor Doortek Net

  Hardware address is 00:A0:C8:5A:D3:B1

  vlan 5 Ip address is 10.1.10.1, netmask is 255.255.255.0

  MTU is 1500 bytes, BW is 100000 Kbit

  ARP type: ARPA; ARP timeout is 20 minutes

  Last clearing of "show interface" counters: 2d 05:38:04

  5 minute input rate 5904 bits/sec, 10 packets/sec

  5 minute output rate 5376 bits/sec, 8 packets/sec

    2110076 packets input, 151280145 bytes

    2108943 unicasts, 1133 broadcasts, 0 multicasts input

    1876313 packets output, 145734195 bytes

    1875630 unicasts, 683 broadcasts, 0 multicasts output

    0 discards

[Anonymous]

I posted a related DHCP and VLAN issue via email. If the MAC address of several VLAN interfaces is the same, how does the DHCP server know what pool to use to assign an IP address to the interface?

[Anonymous]

@bcrinehart - I apologize for the delay in getting back to you. I took some time to test this application out and I was seeing the same results you were. At this point, I would suggest opening up a ticket with Adtran Tech Support to track this issue. Be sure to mention this forum post when you open the ticket. You can open a ticket in several ways:

- By web - Create a Service Request

- By emailing support@adtran.com

- By calling 1-888-423-8726

You can workaround this by assigning a static IP address to the VLAN interfaces instead of using a DHCP host reservation pool. Let us know if you have any questions.

Thanks,

Noor

[Anonymous]

Just and update, I reported this to Adtran post sales support. They confirmed that it is a bug and referred it to their engineering group. They did not provide an expected resolution time.

[Anonymous]

The DHCP POOL command includes the qualifiers:

CLIENT-IDENTIFIER

CLIENT-NAME

HARDWARE-ADDRESS

Hardware address and client identifier appear to be redundant. However,client identifier allows entry of more than the 6 hex digits that are the MAC address. When you do a

SHOW IP DHCP BIND

command, it lists the client identifier and the client name. Through additional testing, I discovered that if I set up a pool to assign an IP address to a device, I can identify the device by client identification provided that I also include the client name. If the client name is not specified or the client name is misspelled, the router does not recognize the device and assigns it an IP address from the network pool.

Specifying the hardware address usually resuts in the client being assigned the desired IP address except in the case of the Netvanta 1234 discussed in this post.

Does anyone know the INTENDED relationship between the client name, client identifier and hardware address?

I've not had an opportunity to test my new findings with the Netvanta 1234. Has anyone been able to assign an IP address to a VLAN interface via DHCP?

[Anonymous]

@bcrinehart -

The client-identifier specifies an ASCII or hexadecimal identifier for the DHCP client. The DHCP server identifies a client by a client-identifier value, which must be unique. If you do not specify one, the DHCP server will concatenate the client hardware type and MAC address to identify the client.

The client-name specifies the name of the client using any standard ASCII character. You should not include the domain name when specifying this field. For example, if you would like to name the client 'test', you should not specify 'test.adtran.com'. This command allows the client to be renamed by the DHCP server.

The hardware-address refers to the MAC address that the DHCP request from the client is sourced from.

I have been able to assign an IP address to a VLAN interface using a generic DHCP pool. However, we have determined from testing that once you attempt to assign an IP to a VLAN interface using a host DHCP pool, it will not work.

Let us know if you have any further questions.

Thanks,

Noor

[Anonymous]

Noor,

Yes, I was able to assign an address to a VLAN interface from a pool using DHCP but was unable to assign a specific address to the VLAN interface using the hardware address or client ID.

Adtran acknowledged that they believe that this is a bug. However, they have not responded as to what they are doing about it.

Sincerely,

Bradley Rinehart, ATSP

[Anonymous · Accepted solution]

- After further investigation, the following was determined:

When a VLAN interface on an AOS device attempts to get an IP address via DHCP, it can’t simply pull an IP address from a DHCP host pool, at least not if the host pool is only trying to identify the AOS device via MAC address.  In order to accurately assign a static/dynamic IP, you need to use a client-identifier to match the VLAN instead.  For example:

ip dhcp pool "1238"

     default router 192.168.50.2

     host 192.168.50.11 255.255.255.0

     client-identifier 00:00:a0:c8:3f:24:b3:00:0a

That DHCP pool will provide an address to an AOS device’s VLAN 10 interface with MAC address 00:a0:c8:3f:24:b3.  The simplest way to determine the client-identifier being used by a dhcp-client is to get a packet capture and check the DHCP Discover message.   If you expand the Discover packet and check the Option 61, Client Identifier section you can see the appropriate value being presented.  If a packet capture isn’t feasible, it’s fairly simple to determine the client-identifier when the DHCP client is an AOS device’s VLAN interface.  In each case, the identifier is the MAC address with a prepended "00:" and then four hex characters that follow the VLAN’s MAC.  The hex characters correlate to the VLAN requesting an address (VLAN “000a” = VLAN 10).

Let us know if you have any questions or issues regarding this.

Thanks,

Noor

[Anonymous]

- I went ahead and flagged this post as “Assumed Answered.”  If any of the responses on this thread assisted you, please mark them as either Correct or Helpful answers with the applicable buttons.  This will make them visible and help other members of the community find solutions more easily.  If you still need assistance, I would be more than happy to continue working with you on this - just let me know in a reply.

Thanks,

Noor

[Anonymous]

:

I went ahead and flagged the "Correct Answer" on this post to make it more visible and help other members of the community find solutions more easily. If you don't feel like the answer I marked was correct, feel free to come back to this post and unmark it and select another in its place with the applicable buttons.  If you still need assistance, we would be more than happy to continue working with you on this - just let us know in a reply.

Thanks,

Levi