I found out that one of my dhcp clients does not send a Parameter Request List (Option 55) in the discover packet.
In this situation, the MicroTik dhcp server does not include the Subnet Mask (Option 1) in the offer.
Other dhcp servers sends this Subnet Mask in any way, (which sounds pretty decent).
Is there a way to "force" RoterOS dhcp server to reply with Subnet Mask even though it was not requested?
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Jagamaster
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Re: DHCP Server does not respond with a Subnet mask
I Have the same problem with HP t5135 thin client.
Netwoark 10.0.3.0/24
Gateway (DHCP-server, DNS, etc) is 10.0.3.100
Normal client:
Problem client (HP thin client 5135) - "Subnet-Mask = 255.255.255.0 " string is absent.
Have anybody any ideas?
Netwoark 10.0.3.0/24
Gateway (DHCP-server, DNS, etc) is 10.0.3.100
Normal client:
Code: Select all
echo: dhcp,debug,packet Parameter-List = Subnet-Mask,Static-Route,Router,Domain-Server,Domain-Name,Unknown(28),Address-Time,Renewal-Time,Unknown(59)
echo: dhcp,debug,packet server1 sending ack with id 2974379535 to 10.0.3.112
echo: dhcp,debug,packet ciaddr = 10.0.3.112
echo: dhcp,debug,packet yiaddr = 10.0.3.112
echo: dhcp,debug,packet siaddr = 10.0.3.100
echo: dhcp,debug,packet chaddr = D4:22:3F:67:34:7E
echo: dhcp,debug,packet Msg-Type = ack
echo: dhcp,debug,packet Server-Id = 10.0.3.100
echo: dhcp,debug,packet Address-Time = 1800
echo: dhcp,debug,packet Subnet-Mask = 255.255.255.0
echo: dhcp,debug,packet Router = 10.0.3.100
echo: dhcp,debug,packet Domain-Server = 10.0.3.100Code: Select all
echo: dhcp,debug,packet Parameter-List = Unknown(180),Unknown(161),Unknown(162),Unknown(184),Unknown(185),Unknown(186),Unknown(187),Unknown(190),Unknown(202),Unknown(203),Router,Domain-Name,Domain-Server
echo: dhcp,info server1 assigned 10.0.3.156 to 00:1C:C4:8C:02:60
echo: dhcp,debug,packet server1 sending ack with id 1292734693 to 10.0.3.156
echo: dhcp,debug,packet ciaddr = 0.0.0.0
echo: dhcp,debug,packet yiaddr = 10.0.3.156
echo: dhcp,debug,packet siaddr = 10.0.3.100
echo: dhcp,debug,packet chaddr = 00:1C:C4:8C:02:60
echo: dhcp,debug,packet Msg-Type = ack
echo: dhcp,debug,packet Server-Id = 10.0.3.100
echo: dhcp,debug,packet Address-Time = 1800
echo: dhcp,debug,packet Router = 10.0.3.100
echo: dhcp,debug,packet Domain-Server = 10.0.3.100Re: DHCP Server does not respond with a Subnet mask
I'm having this same problem, with both RouterOS v5.18 and v6.11
My DHCP server is set to "static-only" and I made static leases for my clients. They do not receive a subnet mask in dhcp offer, so they assume 255.255.0.0 instead of 255.255.255.0 which I am using:
My DHCP server is set to "static-only" and I made static leases for my clients. They do not receive a subnet mask in dhcp offer, so they assume 255.255.0.0 instead of 255.255.255.0 which I am using:
Code: Select all
15:00:56 dhcp,debug,packet ether3-dhcp-serv received request with id 3167770653 from 0.0.0.0
15:00:56 dhcp,debug,packet ciaddr = 0.0.0.0
15:00:56 dhcp,debug,packet chaddr = 00:25:90:D9:CF:F6
15:00:56 dhcp,debug,packet Msg-Type = request
15:00:56 dhcp,debug,packet Client-Id = 01-00-25-90-D9-CF-F6
15:00:56 dhcp,debug,packet Class-Id = "udhcp 1.12.0"
15:00:56 dhcp,debug,packet Address-Request = 172.16.12.111
15:00:56 dhcp,debug,packet Server-Id = 172.16.12.1
15:00:56 dhcp,debug,packet Parameter-List = Subnet-Mask,Router,Domain-Server,Host-Name,Domain-Name,Unknown(28),NTP-Server
15:00:56 dhcp,info ether3-dhcp-serv assigned 172.16.12.111 to 00:25:90:D9:CF:F6
15:00:56 dhcp,debug,packet ether3-dhcp-serv sending ack with id 3167770653 to 172.16.12.111
15:00:56 dhcp,debug,packet ciaddr = 0.0.0.0
15:00:56 dhcp,debug,packet yiaddr = 172.16.12.111
15:00:56 dhcp,debug,packet siaddr = 172.16.12.1
15:00:56 dhcp,debug,packet chaddr = 00:25:90:D9:CF:F6
15:00:56 dhcp,debug,packet Msg-Type = ack
15:00:56 dhcp,debug,packet Server-Id = 172.16.12.1
15:00:56 dhcp,debug,packet Address-Time = 21600
15:00:56 dhcp,debug,packet Domain-Server = 172.16.12.1
15:00:56 dhcp,debug,packet NTP-Server = 17.151.16.14,17.171.4.14
Re: DHCP Server does not respond with a Subnet mask
And if you set "netmask" in dhcp-server network configuration?
Re: DHCP Server does not respond with a Subnet mask
I was able to fix this by changing the DHCP Network "Address" field from "172.16.12.0" to "172.16.12.0/24". Both before and after, I had the "netmask" field set to "24"