Switching

hi guys, ive read some juniper Kbs regarding dhcp-relay options and i cant make it work based on their commands

are there any straight-forward CLI guide out there to follow? 

did anyone try this on their lab or in production environment?

i can ping 4 of my dhcp servers from the qfx console.

but i cannot relay the dhcp packets to the windows dhcp server.

this is the config below;

set forwarding-options dhcp-relay overrides
set forwarding-options dhcp-relay relay-option
set forwarding-options dhcp-relay forward-only
set forwarding-options dhcp-relay server-group 4 1.1.1.1
set forwarding-options dhcp-relay server-group 4 1.1.1.2
set forwarding-options dhcp-relay server-group 4 1.1.1.3

set forwarding-options dhcp-relay server-group 4 1.1.1.4
set forwarding-options dhcp-relay group 4 active-server-group 4-svrs
set forwarding-options dhcp-relay group 4 interface ae0.0
set forwarding-options dhcp-relay group 4 interface irb.10
set forwarding-options dhcp-relay group 4 interface irb.20
set forwarding-options dhcp-relay group 4 interface irb.30
set forwarding-options dhcp-relay group 4 interface irb.40

set forwarding-options dhcp-relay active-server-group 4-svrs

ae0 is trunk port which allows all vlan members.

any suggestioins?

It seems like you have a misconfiguration. Try this 🙂

set forwarding-options dhcp-relay overrides
set forwarding-options dhcp-relay relay-option
set forwarding-options dhcp-relay forward-only
set forwarding-options dhcp-relay server-group 4-srvs 1.1.1.1
set forwarding-options dhcp-relay server-group 4-srvs 1.1.1.2
set forwarding-options dhcp-relay server-group 4-srvs 1.1.1.3
set forwarding-options dhcp-relay server-group 4-srvs 1.1.1.4
set forwarding-options dhcp-relay group 4 active-server-group 4-srvs
set forwarding-options dhcp-relay group 4 interface ae0.0
set forwarding-options dhcp-relay group 4 interface irb.10
set forwarding-options dhcp-relay group 4 interface irb.20
set forwarding-options dhcp-relay group 4 interface irb.30
set forwarding-options dhcp-relay group 4 interface irb.40

set forwarding-options dhcp-relay active-server-group 4-srvs

Thanks EssentialRoot. I will try adjustments of the syntax you provided.

Could be the reasons on the dhcp debug  logs that said ;

Jul 20 16:10:42.584649 No Option-82 overrides
Jul 20 16:10:42.584664 [INFO] jdhcpd_process_relay_option60: No Option-60
Jul 20 16:10:42.584674 jdhcpd_process_relay_generic_option(): af_type is JDHCPD_AF_INET
Jul 20 16:10:42.584688 [INFO] jdhcpd_process_relay_generic_option: Have relay-option
Jul 20 16:10:42.584701 No active-server-group configured

regards,

d

hI Essential,

i tried those adjustments with the commands you provided, but i cannot get it to work.

even directly connected to the qfx. 

there is no issue when im using static  ip address..

any thoughts?

tia,

d

You might want to review the helper statistics and configure the trace options recommended in this troubleshooting kb to confirm that the dhcp request is received by the port and actually forwarded.

https://kb.juniper.net/InfoCenter/index?page=content&id=KB11020

If the forwarding is working, then start down the list of this general kb beginning at step 7

https://kb.juniper.net/InfoCenter/index?page=content&id=KB23335

Hi,

need more information to solve an issue. Many factors could be the cause of problem. 1. Are these IRB interfaces lying in inet.0 routing table or has it's own instance? 2. Are servers correctly working with non-directly connected networks?

hi EssentialRoot,

 everything is in default inet.0

all irbs are reachable (windows dhcp server to qfx and vice versa)

dhcp servers are working quite well. 

i dont have an issue when using static  ip address binding.

maybe something's lacking in the dhcp relay config on the qfx;

-------------------------------------------------------

set forwarding-options dhcp-relay overrides trust-option-82
set forwarding-options dhcp-relay forward-only
set forwarding-options dhcp-relay server-group dhcp-svrs 1.1.1.2
set forwarding-options dhcp-relay server-group dhcp-svrs 1.1.1..3
set forwarding-options dhcp-relay server-group dhcp-svrs 1.1.1..4
set forwarding-options dhcp-relay active-server-group dhcp-svrs
set forwarding-options dhcp-relay group relay-svrs active-server-group dhcp-svrs
set forwarding-options dhcp-relay group relay-svrs interface ae0.0
set forwarding-options dhcp-relay group relay-svrs interface irb.0
set forwarding-options dhcp-relay group relay-svrs interface irb.3
set forwarding-options dhcp-relay group relay-svrs interface irb.8
set forwarding-options dhcp-relay group relay-svrs interface irb.10
set forwarding-options dhcp-relay group relay-svrs interface irb.11
set forwarding-options dhcp-relay group relay-svrs interface irb.12
set forwarding-options dhcp-relay group relay-svrs interface irb.13
set forwarding-options dhcp-relay group relay-svrs interface irb.14
set forwarding-options dhcp-relay group relay-svrs interface irb.15
set forwarding-options dhcp-relay group relay-svrs interface irb.16
set forwarding-options dhcp-relay group relay-svrs interface irb.17
set forwarding-options dhcp-relay group relay-svrs interface irb.18
set forwarding-options dhcp-relay group relay-svrs interface irb.19

tia,

dwayne

Config looks good... almost

If you have no problems with statically configured clients, it's just saying about you have problems with DHCP-RELAY or with DHCP-SERVER 🙂

1. What do you see in the dhcp log of the server?

2. Do you ever see any errors on the server's log? I'm sure, it's something easy and before the eyes.

3. As Steve said earlier: You should turn on traceoption for helper on QFX for much more detailed info gathering.

If ae0.0 just a trunk, you can made "delete forwarding-options dhcp-relay group relay-svrs interface ae0.0" on the QFX

Please run the statistics command to confirm if the packets are been seen and forwarded.

show helper statistics

Configure trace options and post the results after an attempt to get a DHCP address.

set forwarding-options helpers traceoptions file helper
set forwarding-options helpers traceoptions flag bootp
set forwarding-options helpers traceoptions level level

After attempt get the messages

show log helper

hi guys,

sorry for the delayed response on the query.

we found the issue to be on the downstream device with trunk port configured. we reconfigured their lacp settings facing the qfx then add appropriate vlans for the dhcp.

setup is now working.

thanks,

dwayne

What are the changes you made on the downstream devices trunk to make this work ? 

Please, look at this topic - https://forums.juniper.net/t5/Ethernet-Switching/QFX5100-JUNOS-13-2X51-D36-1-Bootp-relay-configuration-example/td-p/277418