Laptop not getting Ip from router dhcp on a certain interface

Installing and Using OpenWrt
1

Hi.
I've got a weird thing going on - I have two LAN interfaces set up - one 'subnet1' - 192.168.0.0/25 and one 'subnet2' 192.168.0.128/25.
Every time I connect my laptop to the second one, I'm not getting an IP. It's very very weird, since I am getting an IP when I connect to the first, and I have clients connected to the second interface who ARE getting IPs.

Any ideas? On the laptop I flushed the IPs on respective wifi interface, deleted and set up the connection again a few times, but nothing. On the router I'm at a loss - since it was working perfectly fine just yesterday and I haven't changed anything.

DHCP:

config dnsmasq
	option domainneeded '1'
	option localise_queries '1'
	option rebind_protection '1'
	option rebind_localhost '1'
	option local '/lan/'
	option domain 'lan'
	option expandhosts '1'
	option authoritative '1'
	option readethers '1'
	option leasefile '/tmp/dhcp.leases'
	option resolvfile '/tmp/resolv.conf.auto'
	option localservice '1'

config dhcp 'subnet1'
	option interface 'subnet1'
	option leasetime '12h'
	option dhcpv6 'server'
	option ra 'server'
	option ra_management '1'
	option start '10'
	option limit '180'

config dhcp 'subnet2'
	option interface 'subnet2'
	option dhcpv6 'server'
	option ra 'server'
	option ra_management '1'
	option start '10'
	option limit '110'
	option leasetime '11h'

config dhcp 'wan'
	option interface 'wan'
	option ignore '1'

config odhcpd 'odhcpd'
	option maindhcp '0'
	option leasefile '/tmp/hosts/odhcpd'
	option leasetrigger '/usr/sbin/odhcpd-update'
	option loglevel '4'

config dhcp 'tenda_lan'        #so 3 interfaces actually, but this one is unrelated to the other two, and works
	option leasetime '12h'
	option interface 'tenda_lan'
	option start '3'
	option limit '10'
2
  • run dnsmasq in full debug and check logread
  • use tcpdump on the faulty transaction / segment / interface

to cover the basics... some pointers ( separate tests, boot router fresh each time )

  • invert the test interfaces
  • wait 7 minutes before attempting to reconnect the second time

for brevvity;

  • post your /etc/config/network /etc/config/firewall
1 Like
3

thank you for the reply, but it had fixed itself - out of nowhere. I'd rebooted the router (and the laptop) a few times with no effect before. But I was setting up something else on the router and I had to reboot it a few more times in the span of an hour. This was right around the time I posted this. And what do you know, just after I posted this message (15 minutes or something like that), everything was back to normal.

1 Like
4

This topic was automatically closed 10 days after the last reply. New replies are no longer allowed.