DHCP Server - Page 2

pedantic · 15-06-2004, 19:00

Quote:

Originally Posted by greencreeper

I would expect that as NTL upgrades and reconfigures the infrastructure some IP addresses will change. Once a week I check all the IPs (UBR, DHCP...) just to make sure nothing has changed and if it has, I update my firewall (ZA Pro). I also guess that as a machine goes searching for a DHCP server to provide it with an IP address, it might not always find the same server. Dunno.

Hi

I understand your point, but how is this new ip showing up in winipcfg ? And to add another twist to this, I log activity on my firewall, and it shows connections to my machine just as it should do. So why is winipcfg showing a different address to the one thats being logged on my firewall ? This is very confusing lol

Regards

ian@huth · 15-06-2004, 19:30

What are the IP addresses involved?

pedantic · 15-06-2004, 19:44

Quote:

Originally Posted by ianathuth

What are the IP addresses involved?

My firewall rules are as follows

DHCP rule .......... Allow udp connections on local port 68 from 10.0.80.71 port 67

2nd DHCP.........Allow udp connections on local port 68 from 10.20.48.1 port 67

3rd rule ........ Allow udp outwards on local port 68 to 255.255.255.255 port 67

For as long as I can remember, I have logs from 10.20.48.1 constantly making connections with me.

Even as we speak its constantly making connections with me, but when I run winipcfg, it informes me that DHCP server address is 10.185.16.134 so how is that address making a connection with me (if indeed it is) as my firewall tells me what connections I have currently. And how is that address connecting to me in the first place as I don't give that address permission to connect to me ?

Regards

Munkeh · 15-06-2004, 20:36

Quote:

Originally Posted by pedantic

My firewall rules are as follows

DHCP rule .......... Allow udp connections on local port 68 from 10.0.80.71 port 67

2nd DHCP.........Allow udp connections on local port 68 from 10.20.48.1 port 67

3rd rule ........ Allow udp outwards on local port 68 to 255.255.255.255 port 67

For as long as I can remember, I have logs from 10.20.48.1 constantly making connections with me.

Even as we speak its constantly making connections with me, but when I run winipcfg, it informes me that DHCP server address is 10.185.16.134 so how is that address making a connection with me (if indeed it is) as my firewall tells me what connections I have currently. And how is that address connecting to me in the first place as I don't give that address permission to connect to me ?

Regards

We're migrating to new dhcp servers at the moment, thats why the address has changed.

The .1 ip is your default gateway, which the initial dhcp discover broadcast is routed through, the subsequent dhcp chatter is unicast so that'll be the .134 address.

You should be able to bin the rules for the .71 ip now

Hope that helpls

pedantic · 15-06-2004, 20:42

Hi

So, let me get this right, the .134 is being routed through .1 as I suspected it might ? so I can get rid of the first DHCP rule and leave the other 2 in ?

Regards

Munkeh · 15-06-2004, 20:48

Quote:

Originally Posted by pedantic

Hi

So, let me get this right, the .134 is being routed through .1 as I suspected it might ? so I can get rid of the first DHCP rule and leave the other 2 in ?

Regards

Yes, feel free to remove the rule for 10.0.80.71 as its no longer in service.

pedantic · 15-06-2004, 21:12

Thank You for your very informative response, much appreciated.

Regards

iadom · 15-06-2004, 21:14

Quote:

Originally Posted by Munkeh

Yes, feel free to remove the rule for 10.0.80.71 as its no longer in service.

Can you confirm that access via STB is still through 10.0.76.70 & 10.0.76.71 in this area.

Munkeh · 15-06-2004, 22:31

Quote:

Originally Posted by iadom

Can you confirm that access via STB is still through 10.0.76.70 & 10.0.76.71 in this area.

Those dhcps have also been taken out of service and traffic migrated to new addresses. (10.185.16.139 & 10.185.16.140 now for your firewall bits n bobs)

HTH

M

greencreeper · 15-06-2004, 22:38

Just out of curiosity - why do those addresses look more like the address of my area's UBR (10.74.16.1) then my area's DCHP servers (62.252.224.21 & 62.252.224.20)?? Is there no consistency - varies from area to area?

Munkeh · 15-06-2004, 23:30

Quote:

Originally Posted by greencreeper

Just out of curiosity - why do those addresses look more like the address of my area's UBR (10.74.16.1) then my area's DCHP servers (62.252.224.21 & 62.252.224.20)?? Is there no consistency - varies from area to area?

The 10.x addresses are classed as private and dont route over the public network, the 62.x addresses are public and do.

You'll be using a cable modem and the other chaps above are likely on bb through the stb, both utililse different architecture for supplying the same service, hence the difference.

Just depends on which service you are using really

greencreeper · 15-06-2004, 23:53

Quote:

Originally Posted by Munkeh

The 10.x addresses are classed as private and dont route over the public network, the 62.x addresses are public and do.

You'll be using a cable modem and the other chaps above are likely on bb through the stb, both utililse different architecture for supplying the same service, hence the difference.

Just depends on which service you are using really

BBKing · 16-06-2004, 06:12

Ick - didn't occur to me to drop a note to Robin.

Basically the STB platform was DHCP'd using lots of big old slow servers. They're being replaced by smaller, more centralised, faster servers. Easier to maintain, cheaper to run, higher capacity. Win/win situation.

The old servers were placed locally to your UBR. The new ones are placed centrally near all the other Interactive servers. Hence the address change.

iadom · 16-06-2004, 08:23

Quote:

Originally Posted by Munkeh

Those dhcps have also been taken out of service and traffic migrated to new addresses. (10.185.16.139 & 10.185.16.140 now for your firewall bits n bobs)

HTH

M

Thanks for that, not checked DHCP for a while but have now added the new ones to trusted zone.

Matth · 16-06-2004, 17:16

My rules allow the two known DHCP servers, the UBR private address, and broadcast address (as remote).

An additional rule allows it if the local address is broadcast - a bit cockeyed, but I had to throw that one in to resolve a problem, as the firewall implied "localhost is ME" without being set.

If your firewall allows it, always best to duplicate, and then disable, the generic DHCP rule, then edit the copy, so that you can quickly revert if you need to.