qdog007 Posted March 29, 2006 Share Posted March 29, 2006 (edited) This is driving me up the wall. Ok…here’s the deal. I have a Dell with Windows 2003 Server and it has 2 NIC’s—but the one that I am concern with has an IP of 192.168.2.1. This is connected to a Linksys switch. I have an IBM (also with Server 2003) that is also connected to that switch. The IBM’s NIC has an IP of 192.168.2.100. Both of these IP addresses are statically configured. The cables, switch, and NICs are working fine...double-checked on them. Both machine indicated that its NIC are indeed “Connected”. But for some reason, they are not able to communicate with one another. I can’t ping either machine from either computer. I have no idea what is going on. There is no firewall on either machines. Both have the same subnet mask. They are on the same subnet…yet can’t ping. Why?Can somehow please tell me how to troubleshoot this? Any advice here would be great. If you need more info, then I’ll be happy to provide more. I just can’t think of anything at this point. Thanks.Q Edited March 29, 2006 by qdog007 Link to comment Share on other sites More sharing options...
fizban2 Posted March 29, 2006 Share Posted March 29, 2006 is the linksys switch configured as a DHCP server? is it possible to check that the 2 IPs you have here are in the range that it is trying to serve Link to comment Share on other sites More sharing options...
qdog007 Posted March 29, 2006 Author Share Posted March 29, 2006 (edited) Thanks for the reply. The Linksys switch have no DHCP capability. I have replaced it with a simple D-Link switch and still no communication between the two machines. So i am ruling out the switch as being the problem. Also the cables are fine. I would love to hear any input regarding this. Edited March 29, 2006 by qdog007 Link to comment Share on other sites More sharing options...
nmX.Memnoch Posted March 29, 2006 Share Posted March 29, 2006 Do you have the gateway IP configured?What is the IP address of the router? Link to comment Share on other sites More sharing options...
qdog007 Posted March 29, 2006 Author Share Posted March 29, 2006 (edited) The default gateway of one my Dell's NIC(the 192.168.2.1) is blank. It is left black because my Dell has another interface, which is 192.168.1.100. This interface's default gateway points to my NAT server (for Internet acccess) which is 192.168.1.1. On my IBM, the default gateway of my NIC (192.168.2.100) is 192.168.2.1. So, the setup looks like this: NAT(1.1)---Dell NIC1(1.100)||Dell NIC2(2.1)---switch-----IBM NIC(2.100).This still baffles me. Initially I thought it was a gateway problem too, but it seems that this is the correct configuration. Any input will be greatly appreciated. Thank you!!Q Edited March 29, 2006 by qdog007 Link to comment Share on other sites More sharing options...
nmX.Memnoch Posted March 29, 2006 Share Posted March 29, 2006 Set the gateway on Dell NIC2 to itself (192.168.2.1).I'm trying to figure out exactly why you have two NICs in that server for internet access when you already have a different NAT server setup...? Link to comment Share on other sites More sharing options...
psuedo Posted March 30, 2006 Share Posted March 30, 2006 Does the switch have an IP address? If so can you ping the switch from either machine? If yes most smart switches have a ping utility, can you ping the servers from the switch? Link to comment Share on other sites More sharing options...
qdog007 Posted March 30, 2006 Author Share Posted March 30, 2006 (edited) MMX: I set the NIC to itself, but they still can't communicate. If the 2 machines are on the same subnet as specify by their IP and subnet mask and they are connected via a simple switch or hub, then theyshould be able to ping each other. Even if there is no default gateway. I mean, they are on the same network. Right??That is why I can't figure this one out. It is just a simple setup.Oh..and the reason I have 2 NICs in my Dell is to make it a router. I use it to learn about routing--for educational purpose.Puedo: The switch is not a smart switch...just a simple 4-port switch. It doesn't have an IP address. Thanks for all your help thus far. I will try to post a diagram of my network when I get a chance. In the meantime, please provide any input. Thanks. Edited March 30, 2006 by qdog007 Link to comment Share on other sites More sharing options...
rookieboy Posted March 30, 2006 Share Posted March 30, 2006 I think you're using the same gateway for both nics, try switching off the nic you're not concerned off, maybe the server does not know where to go Link to comment Share on other sites More sharing options...
Mr Snrub Posted March 30, 2006 Share Posted March 30, 2006 From a command prompt run the command "ipconfig /all" on both machines and put the output here.You say the subnet masks are the same, but you don't say what they are - hopefully 255.255.255.0 or higher?If you have networks 192.168.1.x and 192.168.2.x with subnet masks of only 255.255.0.0 then the NIC binding order will come into play...The gateway setting is irrelevant if the machines are in the same subnet.Is the Dell machine running ISA Server or RRAS or anything, or just multi-homed right now? Link to comment Share on other sites More sharing options...
qdog007 Posted March 30, 2006 Author Share Posted March 30, 2006 Snrub: That is what I thought too. If your PCs are on the same subnet, then their gateway can be left blank and they can still talk. But thanks for the response: Here is my Ipconfig/all output. Thanks for everyone's help.Windows IP Configuration Host Name . . . . . . . . . . . . : Dell Primary Dns Suffix . . . . . . . : qnetwork.com Node Type . . . . . . . . . . . . : Unknown IP Routing Enabled. . . . . . . . : YesEthernet adapter Interface 2.1: Connection-specific DNS Suffix . : Description . . . . . . . . . . . : Realtek RTL8139 Family PCI Fast Ethernet Physical Address. . . . . . . . . : 00-E0-4C-A0-94-D2 DHCP Enabled. . . . . . . . . . . : No IP Address. . . . . . . . . . . . : 192.168.2.1 Subnet Mask . . . . . . . . . . . : 255.255.255.0 Default Gateway . . . . . . . . . : DNS Servers . . . . . . . . . . . : 192.168.1.100 192.168.2.100Ethernet adapter Interface 1.100: Connection-specific DNS Suffix . : Description . . . . . . . . . . . : Broadcom NetXtreme 57xx Gigabit Controlle Physical Address. . . . . . . . . : 00-11-11-32-28-2D DHCP Enabled. . . . . . . . . . . : No IP Address. . . . . . . . . . . . : 192.168.1.100 Subnet Mask . . . . . . . . . . . : 255.255.255.0 Default Gateway . . . . . . . . . : 192.168.1.1 DNS Servers . . . . . . . . . . . : 192.168.1.100 192.168.2.100Windows IP Configuration Host Name . . . . . . . . . . . . : IBM Primary Dns Suffix . . . . . . . : qnetwork.com Node Type . . . . . . . . . . . . : Unknown IP Routing Enabled. . . . . . . . : YesEthernet adapter Interface 2.100: Connection-specific DNS Suffix . : Description . . . . . . . . . . . : Realtek RTL8139 Family PCI Fast Ethernet Physical Address. . . . . . . . . : 00-48-54-62-96-67 DHCP Enabled. . . . . . . . . . . : No IP Address. . . . . . . . . . . . : 192.168.2.100 Subnet Mask . . . . . . . . . . . : 255.255.255.0 Default Gateway . . . . . . . . . : 192.168.2.1 DNS Servers . . . . . . . . . . . : 192.168.1.100 192.168.2.100One final note. Yes, both machines are running RRAS. That is because I was going to set up some static routes later on. Should I disable these? Also, I don't have a ISA server. I have a NAT Server, but this is running on another machine on the 192.168.1.X subnet. Let me know if you need more info. Thanks. Link to comment Share on other sites More sharing options...
Mr Snrub Posted March 30, 2006 Share Posted March 30, 2006 Okay, quick summary of relevant information - stuff that is okay is green, stuff that is wrong is red:DELL:Ethernet adapter Interface 1.100: IP Address. . . . . . . . . . . . : 192.168.1.100 Subnet Mask . . . . . . . . . . . : 255.255.255.0 Default Gateway . . . . . . . . . : 192.168.1.1 DNS Servers . . . . . . . . . . . : 192.168.1.100, 192.168.2.100Ethernet adapter Interface 2.1: IP Address. . . . . . . . . . . . : 192.168.2.1 Subnet Mask . . . . . . . . . . . : 255.255.255.0 Default Gateway . . . . . . . . . : DNS Servers . . . . . . . . . . . : 192.168.1.100, 192.168.2.100IBM:Ethernet adapter Interface 2.100: IP Address. . . . . . . . . . . . : 192.168.2.100 Subnet Mask . . . . . . . . . . . : 255.255.255.0 Default Gateway . . . . . . . . . : 192.168.2.1 DNS Servers . . . . . . . . . . . : 192.168.1.100, 192.168.2.100Why run RRAS on the IBM server?Effecitvely you are setting up a DMZ 192.168.1.0/24 and an internal LAN 192.168.2.0/24, so I can see the need for RRAS on the Dell server so it can route traffic between the networks...DNS on the Dell external interface should point to 192.168.1.1.There should be no DNS on the internal interface.DNS on the IBM interface should point to 192.168.1.1 - let routing take care of communication with the NAT router for DNS resolution, saves you having to configure another DNS proxy internally.One point I will note is that to make a bit more sense I would use the same last digit in the IP addresses of the 2 interfaces on the Dell - my choices would be 192.168.1.254 and 192.168.2.254 - then change the IBM to 192.168.2.200.This just aids in identifying a server at a glance, and routers I tend to number from the top down, static workstations from 1-99, DHCP clients from 100-199 and static servers from 200-250.YMMV, but my advice is pick a scheme and stick to it.Okay, the configuration of the internal network interfaces looks good, so I suspect the RRAS service is loading the IPNAT.SYS driver which may be fouling things up.Action plan:- fix the IP addresses and DNS server entries- make sure ONLY "TCP/IP Protocol" is enabled on the Dell's external interface- remove RRAS on the IBM server- stop the RRAS service on the Dell server- try to ping between these 2 boxes on the 192.168.2.x interfacesIf the ping fails, then immediately after trying do an "arp -a" to list the cached ARP entries to see if we even get a resolution of the IP address to a MAC address - also try temporarily disabling the external interface on the Dell. Link to comment Share on other sites More sharing options...
qdog007 Posted March 30, 2006 Author Share Posted March 30, 2006 (edited) Mr.Snrub: Thank you so much for the detailed response. I am at work right now, but when I get home, I will try out some of your advice. I like your address scheme setup...it makes a lot of sense.Note: I have a local DNS running on my Dell...that is why I have the PCs pointing to it for name resolution. This DNS server is configure to forward all Internet name resolution to my ISP's DNS for resolution. It is also use to resolve internal names. But, yeah....I think maybe RRAS is the culprit and will check them out when I get home. Thanks for your help and I will provide an update on the situation soon. Edited March 30, 2006 by qdog007 Link to comment Share on other sites More sharing options...
jftuga Posted March 31, 2006 Share Posted March 31, 2006 Installing a packet sniffer such as WinDump or Ethereal may help you debug the problem. You could run it on all of your systems to see where the pings and other packets are going to.http://www.winpcap.org/windump/http://www.ethereal.com/-John Link to comment Share on other sites More sharing options...
qdog007 Posted March 31, 2006 Author Share Posted March 31, 2006 Thanks jftuga. I am downloading Ethereal right now. I hope it is easy to use. I really like to know where my packets are going. Doing a tracert doesn't show anything. Thanks for the advice. Link to comment Share on other sites More sharing options...
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