Strange network connectivity problem

Posted by Marc on Server Fault See other posts from Server Fault or by Marc
Published on 2010-03-26T05:15:43Z Indexed on 2010/03/26 5:23 UTC
Read the original article Hit count: 261

Filed under:

ping

|

network

Here is my network connectivity:

cable modem
     |
     |(WAN)
  wrt54g (default gateway, 192.168.1.1) -- earth
     |(LAN)
     |
Simple Switch1
|          |
|          |
|      SimpleSwitch2- neptune      
|        |      |   
|      mars  mercury
| 
|- venus  
| 
|- laptop
|
saturn (Windows AD DC)

simpleSwitch2 was hanging off the wrt54g. I moved it to SW1 during troubleshooting. Nothing described below was any different.

earth is connected via wireless to the wrt54g.

I can ping from laptop to mars, neptune & mercury. I can ping from earth to venus, saturn & laptop.

However, pinging mars, mercury or neptune from earth gives the following result.

Pinging mars.XXX.XXX [192.168.1.105] with 32 bytes of data:
Reply from 192.168.1.122: Destination host unreachable.
Reply from 192.168.1.122: Destination host unreachable.
Reply from 192.168.1.122: Destination host unreachable.
Reply from 192.168.1.122: Destination host unreachable.

Ping statistics for 192.168.1.105:
    Packets: Sent = 4, Received = 4, Lost = 0 (0% loss),

.122 is the address of the machine from which I am pinging.

earth is a Vista machine. Windows firewall is off.

saturn is my DNS & DHCP server.

Can anyone give me any ideas what the h*ll is going on? Clearly the topology is a factor

And yes, I am a space geek.

© Server Fault or respective owner

Related posts about ping

Not able to compile dbus-ping-pong

as seen on Ask Ubuntu - Search for 'Ask Ubuntu'
I have downloaded files from http://cgit.collabora.com/git/user/alban/dbus-ping-pong.git/tree/ I am trying to compile it using the command gcc pkg-config --libs --cflags dbus-1 dbus-glib-1-2 glib-2.0 -o dbus-ping-pong dbus-ping-pong.c However, I get errors: /tmp/ccmJkxXb.o: In function g_once_init_enter: dbus-ping-pong… >>> More
Can ping IP address and nslookup hostname but cannot ping hostname

as seen on Super User - Search for 'Super User'
I have a DNS server set up on one of my machines using BIND 9.7 Everything works fine with it. On my Windows 7 desktop, I have statically-assigned all network values. I have one DNS server set -- my DNS server. On my desktop, I can ping a third machine by IP fine. I can nslookup the hostname of… >>> More
Can ping IP address and nslookup hostname but cannot ping hostname

as seen on Server Fault - Search for 'Server Fault'
On a windows 2003 server I can nslookup www.google.com which returns Server: localhost Address: 127.0.0.1 Non-authoritative answer: Name: www.l.google.com Addresses: 74.125.79.104, 74.125.79.147, 74.125.79.99 Aliases: www.google.com I can then ping 74.125.79.104: Pinging 74.125.79.104… >>> More
Client A can ping server S, but client B cannot

as seen on Server Fault - Search for 'Server Fault'
I moved the question to here from stackoverflow.com http://stackoverflow.com/questions/2917569/unable-to-ping-server-from-client-b-but-able-to-ping-from-client-a-please-help I am trying to configure a IIS 6.0/Windows Server 2003 web server with a ASP.net application. When I try to ping the server… >>> More
Why does ping flooding a domain name freezes and not a direct ip address

as seen on Server Fault - Search for 'Server Fault'
I am wondering why, when ping flooding a domain, the ping flood freezes after a couple of seconds then continues and this freeze, unfreeze continues until i stop the ping flood. When i do the same using the ip it does not freeze. NEVER. i did for example sudo ping -f IP (It does not freeze) then… >>> More

Related posts about network

Changing network type from Unidentified network to Private network on an OpenVPN connection

as seen on Super User - Search for 'Super User'
Is it possible to change the connection type in Windows 7? I have a OpenVPN connection which is identified as "unidentified network" and I do not want to apply certain rules to all unidentified networks in the firewall. How does one conquer this? >>> More
nm-applet gone?

as seen on Ask Ubuntu - Search for 'Ask Ubuntu'
nm-applet seems to have disappeared from my system. I am running 12.10. Here's what I get when I check my package manager logs: ? ~ grep network-manager /var/log/dpkg.log 2012-10-06 10:37:08 upgrade network-manager-gnome:amd64 0.9.6.2-0ubuntu5 0.9.6.2-0ubuntu6 2012-10-06 10:37:08… >>> More
Ops Center 12c - Provisioning Solaris Using a Card-Based NIC

as seen on Oracle Blogs - Search for 'Oracle Blogs'
It's been a long time since last I added something here, but having some conversations this last week, I got inspired to update things. I've been spending a lot of time with Ops Center for managing and installing systems these days. So, I suspect a number of my upcoming posts will be in… >>> More
C# Neural Networks with Encog

as seen on Geeks with Blogs - Search for 'Geeks with Blogs'
Neural Networks · I recently read a book Introduction to Neural Networks for C# , by Jeff Heaton. http://www.amazon.com/Introduction-Neural-Networks-C-2nd/dp/1604390093/ref=sr_1_2?ie=UTF8&s=books&qid=1296821004&sr=8-2-spell. Not the 1st ANN book I've perused, but a nice revision… >>> More
Need for explanation: NetBIOS over TCP/IP on VMware network adapter disturbs access to network share

as seen on Super User - Search for 'Super User'
Some time ago nearly all workstations in our team (Windows XP SP2) exhibited intermittend but frequent delays when accessing shares on the network. Typically the first access to a share which hadn't been accessed for some time resulted in a nearly frozen workstation for up to 30 seconds. Then everything… >>> More