4104gl DHCP fails on some ports -- requiring switch reboot

[Chris Graulich]

Hello--this is a 4104gl switch, default vlan only. Current firmware is G.07.70, although the issue also occurred with earlier firmware. One or more connected PC's become unable to obtain/refresh their ip addresses. Packet trace shows the PC requests, but no response is seen. Other PC's on other ports of the same switch do see proper responses. Rebooting the switch fixes the problem for awhile (many weeks, usually). Other 4104gl's in the building have never exhibited this problem. What do you recommend as the way to troubleshoot further? Thank you! Chris G

[Mohieddin Kharnoub]

Hi

The latests firmware is G.07.79 and i think this switch had many DHCP issues that has been fixed, so try to upgrade to the latest firmware.

http://www.hp.com/rnd/software/j4865799.htm

It could be a DHCP server problem or anything related to it.

Like how this 4100 switch connected to the DHCP? directly or through other switches ?

If you can explain more about your topology and attach the show run of this 4100 switch after deleting any sensitive info.

Good Luck !!!

[Chris Graulich]

All of the various 4104gl's are connected via fiber to a 4108gl. The DHCP server is connected via a gigabit port on the same 4108gl. Only one 4104gl has shown this issue, so far. I will obtain a show run for the unit and will post it (all of the 4104gl's have the same configuration). Also, I will try to obtain/install the firmware update--I think that PCM only had up to .70 available. Thanks for your assistance. Regards, Chris G

[Chris Graulich]

Here is the show run result:

---------
Running configuration:


; J4887A Configuration Editor; Created on release #G.07.70


hostname "(edited)"

snmp-server contact "(edited)"

snmp-server location "(edited)"

cdp run

module 4 type J4864A

module 1 type J4862B

module 2 type J4862B

module 3 type J4862B

interface D1

no lacp

exit

interface D2

no lacp

exit

interface D3

no lacp

exit

interface A1


exit

interface A2

no lacp

exit

interface A3

no lacp

exit

interface A4

no lacp

exit

interface A5

no lacp

exit

interface A6

no lacp

exit

interface A7

no lacp

exit

interface A8

no lacp

exit

no lacp

exit

interface A10

no lacp

exit

interface A11

no lacp

exit

interface A12

no lacp

exit

interface A13

no lacp

exit

interface A14

no lacp

exit

interface A15

no lacp

exit

interface A16

no lacp

interface A17

no lacp

exit

interface A18

no lacp

exit

interface A19

no lacp

exit

interface A20

no lacp

exit

interface A21

no lacp

exit

interface A22

no lacp

exit

interface A23

no lacp

exit

interface A24

exit

interface B1

no lacp

exit

interface B2

no lacp

exit

interface B3

no lacp

exit

interface B4

no lacp

exit

interface B5

no lacp

exit

interface B6

no lacp

exit

interface B7

no lacp

exit

no lacp

exit

interface B9

no lacp

exit

interface B10

no lacp

exit

interface B11

no lacp

exit

interface B12

no lacp

exit

interface B13

no lacp

exit

interface B14

no lacp

exit

interface B15

no lacp

interface B16

no lacp

exit

interface B17

no lacp

exit

interface B18

no lacp

exit

interface B19

no lacp

exit

interface B20

no lacp

exit

interface B21

no lacp

exit

interface B22

no lacp

exit

interface B23

exit

interface B24

no lacp

exit

interface C1

no lacp

exit

interface C2

no lacp

exit

interface C3

no lacp

exit

interface C4

no lacp

exit

interface C5

no lacp

exit

interface C6

no lacp

exit

no lacp

exit

interface C8

no lacp

exit

interface C9

no lacp

exit

interface C10

no lacp

exit

interface C11

no lacp

exit

interface C12

no lacp

exit

interface C13

no lacp

exit

interface C14

no lacp

interface C15

no lacp

exit

interface C16

no lacp

exit

interface C17

no lacp

exit

interface C18

no lacp

exit

interface C19

no lacp

exit

interface C20

no lacp

exit

interface C21

no lacp

exit

interface C22

exit

interface C23

no lacp

exit

interface C24

no lacp

exit

ip default-gateway 10.0.10.1

sntp server 10.0.10.1

timesync sntp

sntp unicast

snmp-server community "(edited)" Unrestricted

snmp-server host 10.0.10.12 "(edited)"

snmp-server host 10.0.10.157 "(edited)"

vlan 1

name "DEFAULT_VLAN"

untagged A1-A24,B1-B24,C1-C24,D1-D3

ip address 10.0.10.22 255.255.255.0

ip igmp high-priority-forward

exit

fault-finder bad-driver sensitivity high

fault-finder bad-transceiver sensitivity high

fault-finder too-long-cable sensitivity high

fault-finder over-bandwidth sensitivity high

fault-finder broadcast-storm sensitivity high

fault-finder loss-of-link sensitivity high

password manager

-------------------end----------------------

[Mohieddin Kharnoub]

Hi Chris

The configuration looks fine, even i think we need to have a look at the configuration of the 4108 switch if you can, also i need from you to do a couple of tests.

When a host can't acquire an IP from the DHCP server, try to assign a static IP, and then ping the DHCP server from the same port without changing anything.

Also, do the Firmware update to the latest.

And, whats the 10.0.10.1? is it the 4108 switch or an external router ? Does it match the Gateway assigned by the DHCP Server ?

If your DHCP server on a different subnet try to add the "IP helper-address [dhcp server ip]" to Vlan1 configuration (its not necessary in your case since you don;t have Vlans, unless you do on the Core switch 4108).

Good Luck !!!

[Chris Graulich]

Hello--
OK, updated to latest firmware. Since the problem is so intermittent it is not clear if the issue is fixed or not.

The 10.0.10.1 is the gateway for all devices and it is also what is handed out by DHCP. The DHCP server is on the 10.0.10.0 network.

If the problem happens again I will set an assigned address and try to ping the dhcp server, as you suggested. One thing to note is that when the problem occurrred I attached a Fluke NetTool to that jack and it showed no DHCP services (which it normally does report) on that jack, but it did show DHCP service when I plugged into any other jack. Actually, the workstation in question also successfully received an address when plugged into a different jack while this was happening. After the switch reboot it was OK.

At any rate, I will have to watch now to see if/when the problem occurs again. Thank you for your help! I appreciate it very much. Regards, cg

[Chris Graulich]

OK--a user just called and it sounds like the issue is back. I will assign an address and see if it can ping the DHCP server without changing anything or rebooting the switch. Will report back...Regards, Chris G

[Chris Graulich]

There were 3 workstations affected this time, and at least one additional wall jack (that is, a machine was brought over to that jack and booted up--no DHCP). The affected machines were connected to different modules in the 4104gl. If I assigned an ip address, they could then ping the DHCP server successfully. Doing a reload on the switch restored all of them to be able to receive addresses via DHCP. Other machines plugged into the same modules as these were unaffected throughout this time. Regards, Chris G

[Chris Graulich]

Closing thread since the problem has not been observed for some months.