MAJOR DHCP server issues

RouterOS General
1

Hello,

We have a large wireless network with people that are using wireless bride SM to connect their LinkSys routers or PCs.

Lots of people are having to reboot their routers EVERY DAY, or 4-5 times a day!!! I don’t know what the heck is going on, but people are getting very very angry. Please help! :frowning:

We have Mikrotik 4.10 with DHCP server enabled with the following parameters:
Lease Time: 1d 00:00:00
Address Pool: dhcp1
Authoritative: Yes
Bootp support: Static
Add Arp for Leases (checked)
Always broadcast (checked)

We have 11 dhcp network addresses being handed out.

There seems to be some lease syncing issue. If customers reboot their router and get a new IP address, they are able to get online. Or, if customers, connect another PC, they are able to get online. Looks like there is some MAC address mapping or conflict issue. Any help is appreciated.

J

2

Try to upgrade to V 5.7 (Latest) and I think increase the lease time.

We have 11 dhcp network addresses being handed out.

Do you mean You have 11 DHCP network in one router or different?
Let us know more about your network such as Network diagram!

3

Yes, the router has 11 IP address pools.

Internet ----> Mikrotik -----> Wireless Bridge AP -----> Wireless Bridge SM ------> LinkSys Router (or PC) -----> Customer

Mikrotik IP:
207.xx.xx.1
209.xx.xx.1
164.xx.xx.1
165.xx.xx.1
201.xx.xx.1
158.xx.xx.x
etc. (11 total)

IP Pools (start from pool1 and go through pool11)
pool1 = 207.xx.xx.2 - 207.xx.xx.254
pool2 = 209.xx.xx.1 - 209.xx.xx.254
pool3 = 164.xx.xx.1 - 164.xx.xx.254
(etc. 11 total)

I would like to hand out DHCP IP’s from these pools to the clients.

I think that I need to change the Src. Address field from 0.0.0.0 to the IP list of the router (i.e. 207.xx.xx.0)?

Anyone have some thoughts, or seen this issue before. Need help ASAP!!! :frowning:

Thanks,
J

4

I think where my issues lies is in the unclear configuration guide below:

“src-address (IP address; default: 0.0.0.0) - the address which the DHCP client must send requests to in order to renew an IP address lease. If there is only one static address on the DHCP server interface and the source-address is left as 0.0.0.0, then the static address will be used. If there are multiple addresses on the interface, an address in the same subnet as the range of given addresses should be used”

Since I am using multiple addresses on the interface, an address in the same subnet as the range of given addresses should be used.

The question is: What address should I use? The IP address of the interface?

Anyone set this up before?

5

I have checked http://wiki.mikrotik.com/wiki/Manual:IP/DHCP_Server which you mentioned to it.
Yes, It should be the DHCP interface. but there is on thing, because of different network that you used, The clients should know route to the Router Interface!
Try one of router interface

6

Which IP? I have 11 on the interface!!

7

I think what it is saying is that you have to use an IP address on the same subnet as the given IP addresses.

So, this means, that you can not have multiple IP addresses that are in different (non-continuous) networks.

So…I don’t know of any way to fix this.

Anyone else have this issue?..or have a work-around?

8

you can have multiple subnets, just make sure to have them all setup in the networks tab.

you are probably experiencing packet loss, bad bridging, or another client satisfying the dhcp address request before yours does. how many devices are on that bridge?

9

I have all the networks (11 total) set up in the networks tab.

I don’t think packet loss is as issue because customers routers have 5-10 IP addresses in their bridge table. To get them working, I have to set the wireless SM in NAT mode, or, I have to have them get another router to plug in.

Bad bridging could be an issue…I don’t know exactly what this means.

There is no other DHCP server on the network because all the IP’s the customers are getting are legitimate from our IP block.

Any other thoughts?

J

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