Network Connection Problem

**cryingvalor** · 02-04-2007, 09:00 PM

- hey guys i have a problem with one of our computer connected to the network.i just recently change the ip address used by our network from 192.168.0.0/24 to 192.168.1.0/24 and nothing more i just changed the ip address.then one of our computer cant connect to the network, its using a DHCP ip address assigned by our DHCP server. the computer cant be ping and when you try to ping from the computer there is an error saying "Negotiating IP Security".....

muggy · 02-06-2007, 12:28 AM

what is the message that you get on your working computer if you ping this one(the one with the issue)? are you getting a valid IP on this comp in the new range?

does it show "Negotiating IP Security" when you try to ping both the comp and the gateway? and does it show that message irrespective of how many times you try to ping?

its some issue with IPSec or most probably IKE

**cryingvalor** · 02-06-2007, 12:38 AM

-if you ping it, it just say "Request time out" thats the only error...but if try to ping other computers using the computer(with an issue) it says Negotiating IP Security....

muggy · 02-06-2007, 01:09 AM

it could be something to do with IKE. which version of Windows are you using? assuming its some NT based OS, ensure that the IPSec Policy Agent service or IPSEC services is running.

ensure audits are enabled for the success and failure of 'Audit Logon Events' attribute of the service. then try to ping the gateway or the other computer. the IKE service(which runs as a part of IPSec) will make audit entries and tell us why the negotiation is failing

i guess the reason why this issue is cropping up is that the traffic between the devices is not getting secured by IPSec

**cryingvalor** · 02-06-2007, 02:05 AM

-the unit with an issue is using XP2
-im sorry but im not familiar with IPSec....where can i find the settings for this IPSec?

muggy · 02-06-2007, 02:22 AM

before we get into IPSec trouble-shooting lets take a look at your network settings.

have you checked your software firewall? i understand that it was working fine before you changed the IP, but is it possible that the firewall may have been configured to allow only the previous IP and hence is blocking this new(apparently not trusted) IP?

also do you have any static IP settings?

**cryingvalor** · 02-06-2007, 08:01 AM

-

Quote:

have you checked your software firewall?

-are you pointing to XP firewall?...actually i set it to allow everything then turn it off but same problem.
- our network is using static ip address before. when i changed the ip address i set all units except the servers to use DHCP...i also tried putting again static ip address on the XP2 unit with an issue but still same problem...

muggy · 02-06-2007, 08:59 PM

i was also referring to third-party firewalls like Norton, McAfee or Trend? have you disabled or configured these if you have 'em?

i haven't trouble-shot IPSec on XP before, only Win2K. here's a document on IPSec trouble-shooting for 2k....see if it works for XP too

IPSec trouble-shooting in Win2k

**cryingvalor** · 02-06-2007, 10:53 PM

- what i have is just free AVG antivirus...
- thanks for the link...

02-04-2007, 09:00 PM	#1 (permalink)
cryingvalor TSF Enthusiast Join Date: Nov 2006 Posts: 510 OS: XP2,WIN03,UBUNTU,CentOS,Bayanihan,FEDORA 8	Network Connection Problem - hey guys i have a problem with one of our computer connected to the network.i just recently change the ip address used by our network from 192.168.0.0/24 to 192.168.1.0/24 and nothing more i just changed the ip address.then one of our computer cant connect to the network, its using a DHCP ip address assigned by our DHCP server. the computer cant be ping and when you try to ping from the computer there is an error saying "Negotiating IP Security".....

02-06-2007, 12:28 AM	#2 (permalink)
muggy Registered User Join Date: Sep 2006 Location: Bangalore, India Posts: 121 OS: XP, Vista	what is the message that you get on your working computer if you ping this one(the one with the issue)? are you getting a valid IP on this comp in the new range? does it show "Negotiating IP Security" when you try to ping both the comp and the gateway? and does it show that message irrespective of how many times you try to ping? its some issue with IPSec or most probably IKE

02-06-2007, 12:38 AM	#3 (permalink)
cryingvalor TSF Enthusiast Join Date: Nov 2006 Posts: 510 OS: XP2,WIN03,UBUNTU,CentOS,Bayanihan,FEDORA 8	-if you ping it, it just say "Request time out" thats the only error...but if try to ping other computers using the computer(with an issue) it says Negotiating IP Security....

02-06-2007, 01:09 AM	#4 (permalink)
muggy Registered User Join Date: Sep 2006 Location: Bangalore, India Posts: 121 OS: XP, Vista	it could be something to do with IKE. which version of Windows are you using? assuming its some NT based OS, ensure that the IPSec Policy Agent service or IPSEC services is running. ensure audits are enabled for the success and failure of 'Audit Logon Events' attribute of the service. then try to ping the gateway or the other computer. the IKE service(which runs as a part of IPSec) will make audit entries and tell us why the negotiation is failing i guess the reason why this issue is cropping up is that the traffic between the devices is not getting secured by IPSec

02-06-2007, 02:05 AM	#5 (permalink)
cryingvalor TSF Enthusiast Join Date: Nov 2006 Posts: 510 OS: XP2,WIN03,UBUNTU,CentOS,Bayanihan,FEDORA 8	-the unit with an issue is using XP2 -im sorry but im not familiar with IPSec....where can i find the settings for this IPSec?

02-06-2007, 02:22 AM	#6 (permalink)
muggy Registered User Join Date: Sep 2006 Location: Bangalore, India Posts: 121 OS: XP, Vista	before we get into IPSec trouble-shooting lets take a look at your network settings. have you checked your software firewall? i understand that it was working fine before you changed the IP, but is it possible that the firewall may have been configured to allow only the previous IP and hence is blocking this new(apparently not trusted) IP? also do you have any static IP settings?

02-06-2007, 08:59 PM	#8 (permalink)
muggy Registered User Join Date: Sep 2006 Location: Bangalore, India Posts: 121 OS: XP, Vista	i was also referring to third-party firewalls like Norton, McAfee or Trend? have you disabled or configured these if you have 'em? i haven't trouble-shot IPSec on XP before, only Win2K. here's a document on IPSec trouble-shooting for 2k....see if it works for XP too IPSec trouble-shooting in Win2k

02-06-2007, 10:53 PM	#9 (permalink)
cryingvalor TSF Enthusiast Join Date: Nov 2006 Posts: 510 OS: XP2,WIN03,UBUNTU,CentOS,Bayanihan,FEDORA 8	- what i have is just free AVG antivirus... - thanks for the link...