Cannot ping/access internal LAN computers

**AndrewTheArt** · 11-19-2007

Hey all -

I recently did a massive Smart Upgrade and upgraded all my packages. This might be besides the point, but I'm mentioning it just in case. Anyway, it installed kernel 2.24 rc2, which I didn't have the headers or source for, so I couldn't rebuild some of my kernel modules (vmware, etc) - thusly I downgraded back to 2.18.

I got back into a GUI and everything was going great. I could browse the web perfectly, etc. Until I realized that I couldn't ping anybody within my own network!!!

Code:

linux-drew:~ # ping 192.168.1.104
PING 192.168.1.104 (192.168.1.104) 56(84) bytes of data.
From 192.168.1.103: icmp_seq=1 Destination Host Unreachable
From 192.168.1.103 icmp_seq=1 Destination Host Unreachable
From 192.168.1.103 icmp_seq=2 Destination Host Unreachable
From 192.168.1.103 icmp_seq=3 Destination Host Unreachable
From 192.168.1.103 icmp_seq=4 Destination Host Unreachable
From 192.168.1.103 icmp_seq=5 Destination Host Unreachable
From 192.168.1.103 icmp_seq=6 Destination Host Unreachable

I also found that Samba was broken, but this didn't surprise me considering that I couldn't reach my computers with a ping.

Code:

linux-drew:~ # smbclient //oemcomputer/spool
Error connecting to 192.168.1.104 (No route to host)
Connection to oemcomputer failed

Any ideas? What could have broken? My other machines (windows machines) can all see each other fine ATM. From what I can see, my /etc/hosts hasn't changed either.

Code:

linux-drew:~ # route -n
Kernel IP routing table
Destination	 Gateway		 Genmask		 Flags Metric Ref	Use Iface
192.168.1.0	 0.0.0.0		 255.255.255.0   U	 0	  0		0 eth0
172.16.15.0	 0.0.0.0		 255.255.255.0   U	 0	  0		0 vmnet8
192.168.89.0	0.0.0.0		 255.255.255.0   U	 0	  0		0 vmnet1
169.254.0.0	 0.0.0.0		 255.255.0.0	 U	 0	  0		0 eth0
127.0.0.0	   0.0.0.0		 255.0.0.0	   U	 0	  0		0 lo
0.0.0.0		 192.168.1.1	 0.0.0.0		 UG	0	  0		0 eth0

Code:

linux-drew:~ # arp
Address				  HWtype  HWaddress		   Flags Mask			Iface
oemcomputer					  (incomplete)							  eth0
192.168.1.1			  ether   <private mac address is censored here>   C					 eth0

Code:

linux-drew:~ # ifconfig
eth0	  Link encap:Ethernet  HWaddr 00:0C:F1:EE:CA:AF
		  inet addr:192.168.1.103  Bcast:192.168.1.255  Mask:255.255.255.0
		  inet6 addr: fe80::20c:f1ff:feee:caaf/64 Scope:Link
		  UP BROADCAST NOTRAILERS RUNNING MULTICAST  MTU:1500  Metric:1
		  RX packets:5081 errors:0 dropped:0 overruns:0 frame:0
		  TX packets:5702 errors:0 dropped:0 overruns:0 carrier:0
		  collisions:0 txqueuelen:1000
		  RX bytes:3499550 (3.3 Mb)  TX bytes:2298648 (2.1 Mb)

lo		Link encap:Local Loopback
		  inet addr:127.0.0.1  Mask:255.0.0.0
		  inet6 addr: ::1/128 Scope:Host
		  UP LOOPBACK RUNNING  MTU:16436  Metric:1
		  RX packets:629 errors:0 dropped:0 overruns:0 frame:0
		  TX packets:629 errors:0 dropped:0 overruns:0 carrier:0
		  collisions:0 txqueuelen:0
		  RX bytes:145911 (142.4 Kb)  TX bytes:145911 (142.4 Kb)

vmnet1	Link encap:Ethernet  HWaddr 00:50:56:C0:00:01
		  inet addr:192.168.89.1  Bcast:192.168.89.255  Mask:255.255.255.0
		  inet6 addr: fe80::250:56ff:fec0:1/64 Scope:Link
		  UP BROADCAST RUNNING MULTICAST  MTU:1500  Metric:1
		  RX packets:0 errors:0 dropped:0 overruns:0 frame:0
		  TX packets:6 errors:0 dropped:0 overruns:0 carrier:0
		  collisions:0 txqueuelen:1000
		  RX bytes:0 (0.0 b)  TX bytes:0 (0.0 b)

vmnet8	Link encap:Ethernet  HWaddr 00:50:56:C0:00:08
		  inet addr:172.16.15.1  Bcast:172.16.15.255  Mask:255.255.255.0
		  inet6 addr: fe80::250:56ff:fec0:8/64 Scope:Link
		  UP BROADCAST RUNNING MULTICAST  MTU:1500  Metric:1
		  RX packets:0 errors:0 dropped:0 overruns:0 frame:0
		  TX packets:6 errors:0 dropped:0 overruns:0 carrier:0
		  collisions:0 txqueuelen:1000
		  RX bytes:0 (0.0 b)  TX bytes:0 (0.0 b)

Running openSUSE 10.2 in a home network.

**Thrillhouse** · 11-19-2007

It looks like your routing table got flushed but that's odd because you can still browse the internet. Maybe SuSE is detecting your router for you and routing internet traffic through there but your ICMP messages (ping) are getting lost. Try adding your router's IP back into your routing table:

Code:

#route add default gw 192.168.1.*

Replace * with the appropriate number corresponding to your router's IP.

**AndrewTheArt** · 11-19-2007

Originally Posted by Thrillhouse

It looks like your routing table got flushed but that's odd because you can still browse the internet. Maybe SuSE is detecting your router for you and routing internet traffic through there but your ICMP messages (ping) are getting lost. Try adding your router's IP back into your routing table:

Code:

#route add default gw 192.168.1.*

Replace * with the appropriate number corresponding to your router's IP.

I believe our router's IP is 192.168.1.1 so this is what I got back...

Code:

linux-drew:~ # route add default gw 192.168.1.1
SIOCADDRT: File exists

**Thrillhouse** · 11-19-2007

Ah, try removing the one route from your table that has 192.168.1.1 as its gw and then try again:

EDIT: Sorry about that, you don't want to do what I posted. Try this instead:

Code:

#route add -net 192.168.1.0 gw 192.168.1.1

**AndrewTheArt** · 11-19-2007

Originally Posted by Thrillhouse

Ah, try removing the one route from your table that has 192.168.1.1 as its gw and then try again:

EDIT: Sorry about that, you don't want to do what I posted. Try this instead:

Code:

#route add -net 192.168.1.0 gw 192.168.1.1

Code:

linux-drew:~ # route add -net 192.168.1.0 gw 192.168.1.1
SIOCADDRT: Invalid argument

**Thrillhouse** · 11-19-2007

OK, try appending the netmask to the net:

Code:

#route add -net 192.168.1.0/24 gw 192.168.1.1

**AndrewTheArt** · 11-19-2007

Originally Posted by Thrillhouse

OK, try appending the netmask to the net:

Code:

#route add -net 192.168.1.0/24 gw 192.168.1.1

That didn't fix the issue.

I'm fairly certain that downgrading and then upgrading the kernel reset my DNS server configuration and settings. In YaST, it is asking me to set this up when I go the YaST DNS server module. Problem is, I have no idea how to set it up. I think it was autoconfigured when SUSE first installed.

Any insight would be greatly appreciated.

**Thrillhouse** · 11-20-2007

I don't think this is a DNS issue. If it was, you would have received different errors from both the ping and samba commands unless you had the 104 machine in your hosts file. And you wouldn't be getting errors like this:

Code:

Error connecting to 192.168.1.104 (No route to host)

Can you post your up to date routing table? If 192.168.1.0 doesn't have 192.168.1.1 set as the gateway, you're probably not going to be able to go any further. You'll have to delete that entry and then re-add it with the correct gateway. Then, if it still doesn't work, we can begin to explore other options.

**AndrewTheArt** · 11-20-2007

Routing table for SUSE Linux machine -

Code:

Kernel IP routing table
Destination     Gateway         Genmask         Flags Metric Ref    Use Iface
192.168.1.0     0.0.0.0         255.255.255.0   U     0      0        0 eth0
169.254.0.0     0.0.0.0         255.255.0.0     U     0      0        0 eth0
127.0.0.0       0.0.0.0         255.0.0.0       U     0      0        0 lo
0.0.0.0         192.168.1.1     0.0.0.0         UG    0      0        0 eth0

Routing table for Vista machine running Cygwin -

Code:

===========================================================================
Interface List
 11 ...**************** ...... Atheros AR5007EG Wireless Network Adapter
  9 ...**************** ...... Realtek RTL8101 Family PCI-E Fast Ethernet NIC (NDIS 6.0)
  1 ........................... Software Loopback Interface 1
 10 ...00 00 00 00 00 00 00 e0  isatap.{C9F2221A-5FA0-4D1C-AB60-041025AF333F}
  8 ...00 00 00 00 00 00 00 e0  6TO4 Adapter
 13 ...00 00 00 00 00 00 00 e0  isatap.tx.rr.com
 12 ...**************** ...... Teredo Tunneling Pseudo-Interface
===========================================================================

IPv4 Route Table
===========================================================================
Active Routes:
Network Destination        Netmask          Gateway       Interface  Metric
          0.0.0.0          0.0.0.0      192.168.1.1    192.168.1.110     30
        127.0.0.0        255.0.0.0         On-link         127.0.0.1    306
        127.0.0.1  255.255.255.255         On-link         127.0.0.1    306
  127.255.255.255  255.255.255.255         On-link         127.0.0.1    306
      192.168.1.0    255.255.255.0         On-link     192.168.1.110    286
    192.168.1.110  255.255.255.255         On-link     192.168.1.110    286
    192.168.1.255  255.255.255.255         On-link     192.168.1.110    286
        224.0.0.0        240.0.0.0         On-link         127.0.0.1    306
        224.0.0.0        240.0.0.0         On-link     192.168.1.110    286
  255.255.255.255  255.255.255.255         On-link         127.0.0.1    306
  255.255.255.255  255.255.255.255         On-link     192.168.1.110    286
===========================================================================
Persistent Routes:
  None

IPv6 Route Table
===========================================================================
Active Routes:
 If Metric Network Destination      Gateway
 12     18 ::/0                     On-link
  1    306 ::1/128                  On-link
 12     18 2001::/32                On-link
 12    266 2001:0:4136:e388:8a0:1cda:3f57:fe91/128
                                    On-link
 11    286 fe80::/64                On-link
 12    266 fe80::/64                On-link
 13    296 fe80::5efe:192.168.1.110/128
                                    On-link
 12    266 fe80::8a0:1cda:3f57:fe91/128
                                    On-link
 11    286 fe80::7010:f606:8c8d:a32b/128
                                    On-link
  1    306 ff00::/8                 On-link
 12    266 ff00::/8                 On-link
 11    286 ff00::/8                 On-link
===========================================================================
Persistent Routes:
  None

How can I make them the same? Lol

PS - Blocked out MAC address for security reasons

**HROAdmin26** · 11-20-2007

Your routing table is fine. DNS is also not involved - "ping ip" needs no name resolution.

You are getting "no route to host" because your eth0 NIC cannot get the MAC address tied to the .104 IP address. The routing table correctly shows "if you need to reach the 192.168.1.0/24 network, just use eth0."

Beyond that, eth0 has to make an arp request that says "who has IP .104"? Your machine can't make that request, or the .104 machine isn't responding.

You can confirm this already, because "ping .104" fails, and then the arp table has no entry for .104.

Something is blocking or has hosed your arp requests. This would only affect access to your local subnet, since your machine doesn't make arp requests to machines that reside on other subnets. Is iptables enabled at all?

Edit: After trying a "ping .104", check your messages log - anything?

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