[SOLVED] ping only goes one way

[clariceoshea]

make a diagram

US Robotics broadband router...iinput from cable modem...

broadband router with two "output" ethernet cables going to each of two computers
better description

(A) "east computer" with 2 OS
(1) Fedora 17
computer name = Precision-380

ping landonkelsey-PC works

(2) XP Prof SP3
computer name = Precision380

ping landonkelsey-PC works



(B) "west computer" with System 7
computer name = landonkelsey-PC

ping Precision380 does NOT work
when Precision380 is active
ping Precision-380 does NOT work
when Precision-380 is active

[stevea]

Does the Fedora system have it's IP and ROUTE setup correctly. If Fedora doesn't have a route then it can't reply to the ping.

As root you can
ip addr
ip route
and maybe post th results.

Especially check that the default route has your router gateway address.

[root@crucibulum etc]# ip route
default via 192.168.42.1 dev wlan0 proto static
192.168.42.0/24 dev wlan0 proto kernel scope link src 192.168.42.100
192.168.122.0/24 dev virbr0 proto kernel scope link src 192.168.122.1

[clariceoshea]

C:\>ipconfig /all

Windows IP Configuration

Host Name . . . . . . . . . . . . : landonkelsey-PC
Primary Dns Suffix . . . . . . . :
Node Type . . . . . . . . . . . . : Hybrid
IP Routing Enabled. . . . . . . . : No
WINS Proxy Enabled. . . . . . . . : No
DNS Suffix Search List. . . . . . : rchrd.phub.net.cable.rogers.com

Ethernet adapter Local Area Connection:

Connection-specific DNS Suffix . : rchrd.phub.net.cable.rogers.com
Description . . . . . . . . . . . : Intel(R) 82579LM Gigabit Network Connect
on
Physical Address. . . . . . . . . : 18-03-73-E3-64-1F
DHCP Enabled. . . . . . . . . . . : Yes
Autoconfiguration Enabled . . . . : Yes
Link-local IPv6 Address . . . . . : fe80::7d29:240c:39d1:6bd1%11(Preferred)
IPv4 Address. . . . . . . . . . . : 192.168.123.101(Preferred)
Subnet Mask . . . . . . . . . . . : 255.255.255.0
Lease Obtained. . . . . . . . . . : Thursday, June 28, 2012 10:27:36 PM
Lease Expires . . . . . . . . . . : Thursday, August 09, 2012 2:51:15 PM
Default Gateway . . . . . . . . . : 192.168.123.254
DHCP Server . . . . . . . . . . . : 192.168.123.254
DHCPv6 IAID . . . . . . . . . . . : 236454771
DHCPv6 Client DUID. . . . . . . . : 00-01-00-01-16-EC-22-5C-18-03-73-E3-64-1

DNS Servers . . . . . . . . . . . : 192.168.123.254
NetBIOS over Tcpip. . . . . . . . : Enabled

Tunnel adapter isatap.rchrd.phub.net.cable.rogers.com:

Media State . . . . . . . . . . . : Media disconnected
Connection-specific DNS Suffix . : rchrd.phub.net.cable.rogers.com
Description . . . . . . . . . . . : Microsoft ISATAP Adapter
Physical Address. . . . . . . . . : 00-00-00-00-00-00-00-E0
DHCP Enabled. . . . . . . . . . . : No
Autoconfiguration Enabled . . . . : Yes

Tunnel adapter 6TO4 Adapter:

Media State . . . . . . . . . . . : Media disconnected
Connection-specific DNS Suffix . :
Description . . . . . . . . . . . : Microsoft 6to4 Adapter
Physical Address. . . . . . . . . : 00-00-00-00-00-00-00-E0
DHCP Enabled. . . . . . . . . . . : No
Autoconfiguration Enabled . . . . : Yes

Tunnel adapter Teredo Tunneling Pseudo-Interface:

Connection-specific DNS Suffix . :
Description . . . . . . . . . . . : Teredo Tunneling Pseudo-Interface
Physical Address. . . . . . . . . : 00-00-00-00-00-00-00-E0
DHCP Enabled. . . . . . . . . . . : No
Autoconfiguration Enabled . . . . : Yes
IPv6 Address. . . . . . . . . . . : 2001:0:4137:9e76:18b9:500:3f57:849a(Pref
rred)
Link-local IPv6 Address . . . . . : fe80::18b9:500:3f57:849a%13(Preferred)
Default Gateway . . . . . . . . . : ::
NetBIOS over Tcpip. . . . . . . . : Disabled

C:\>

[clariceoshea]

IP Routing Enabled. . . . . . . . : No

[stevea]

So you completely changed post #1 and you still refuse to provide the basic info requested on the Linux system.

"does NOT work" is not a proper description. You need to post the exact result, like a "Destination Host Unreachable" or a "100% packet loss" or other message.

[clariceoshea]

error
C:\>ping Precision-380
Ping request could not find host Precision-380. Please check the name and try again.

ifconfig is Linux/Fedora
ipconfig is System 7

[landon@Precision-380 etc]$ ifconfig
lo: flags=73<UP,LOOPBACK,RUNNING> mtu 16436
inet 127.0.0.1 netmask 255.0.0.0
inet6 ::1 prefixlen 128 scopeid 0x10<host>
loop txqueuelen 0 (Local Loopback)
RX packets 10 bytes 924 (924.0 B)
RX errors 0 dropped 0 overruns 0 frame 0
TX packets 10 bytes 924 (924.0 B)
TX errors 0 dropped 0 overruns 0 carrier 0 collisions 0

p4p1: flags=4163<UP,BROADCAST,RUNNING,MULTICAST> mtu 1500
inet 192.168.123.101 netmask 255.255.255.0 broadcast 192.168.123.255
inet6 fe80::213:72ff:fe21:cf41 prefixlen 64 scopeid 0x20<link>
ether 00:13:72:21:cf:41 txqueuelen 1000 (Ethernet)
RX packets 1110 bytes 956028 (933.6 KiB)
RX errors 0 dropped 0 overruns 0 frame 0
TX packets 1110 bytes 242092 (236.4 KiB)
TX errors 0 dropped 0 overruns 0 carrier 0 collisions 0
device interrupt 17

[landon@Precision-380 etc]$


C:\>ipconfig

Windows IP Configuration


Ethernet adapter Local Area Connection:

Connection-specific DNS Suffix . : rchrd.phub.net.cable.rogers.com
Link-local IPv6 Address . . . . . : fe80::7d29:240c:39d1:6bd1%11
IPv4 Address. . . . . . . . . . . : 192.168.123.100
Subnet Mask . . . . . . . . . . . : 255.255.255.0
Default Gateway . . . . . . . . . : 192.168.123.254

Tunnel adapter isatap.rchrd.phub.net.cable.rogers.com:

Media State . . . . . . . . . . . : Media disconnected
Connection-specific DNS Suffix . : rchrd.phub.net.cable.rogers.com

Tunnel adapter 6TO4 Adapter:

Media State . . . . . . . . . . . : Media disconnected
Connection-specific DNS Suffix . :

Tunnel adapter Teredo Tunneling Pseudo-Interface:

Connection-specific DNS Suffix . :
IPv6 Address. . . . . . . . . . . : 2001:0:4137:9e76:1009:78b:3f57:849b
Link-local IPv6 Address . . . . . : fe80::1009:78b:3f57:849b%13
Default Gateway . . . . . . . . . : ::

---------- Post added at 06:01 PM ---------- Previous post was at 05:17 PM ----------

the failing pings do work if dotted decimal ip addresses used

ping 192.168.123.101

---------- Post added at 06:13 PM ---------- Previous post was at 06:01 PM ----------

I tried reregistering local dns:

C:\>ipconfig /help

Error: unrecognized or incomplete command line.

USAGE:
ipconfig [/allcompartments] [/? | /all |
/renew [adapter] | /release [adapter] |
/renew6 [adapter] | /release6 [adapter] |
/flushdns | /displaydns | /registerdns |
/showclassid adapter |
/setclassid adapter [classid] |
/showclassid6 adapter |
/setclassid6 adapter [classid] ]

where
adapter Connection name
(wildcard characters * and ? allowed, see examples)

Options:
/? Display this help message
/all Display full configuration information.
/release Release the IPv4 address for the specified adapter.
/release6 Release the IPv6 address for the specified adapter.
/renew Renew the IPv4 address for the specified adapter.
/renew6 Renew the IPv6 address for the specified adapter.
/flushdns Purges the DNS Resolver cache.
/registerdns Refreshes all DHCP leases and re-registers DNS names
/displaydns Display the contents of the DNS Resolver Cache.
/showclassid Displays all the dhcp class IDs allowed for adapter.
/setclassid Modifies the dhcp class id.
/showclassid6 Displays all the IPv6 DHCP class IDs allowed for adapter.
/setclassid6 Modifies the IPv6 DHCP class id.


The default is to display only the IP address, subnet mask and
default gateway for each adapter bound to TCP/IP.

For Release and Renew, if no adapter name is specified, then the IP address
leases for all adapters bound to TCP/IP will be released or renewed.

For Setclassid and Setclassid6, if no ClassId is specified, then the ClassId is removed

Examples:
> ipconfig ... Show information
> ipconfig /all ... Show detailed information
> ipconfig /renew ... renew all adapters
> ipconfig /renew EL* ... renew any connection that has its
name starting with EL
> ipconfig /release *Con* ... release all matching connections,
eg. "Local Area Connection 1" or
"Local Area Connection 2"
> ipconfig /allcompartments ... Show information about all
compartments
> ipconfig /allcompartments /all ... Show detailed information about all
compartments

[stevea]

Originally Posted by clariceoshea

error
C:\>ping Precision-380
Ping request could not find host Precision-380. Please check the name and try again.
[...]

the failing pings do work if dotted decimal ip addresses used

ping 192.168.123.101

Congratulations - youve finally posted enough info to diagnose the problem,
It's unfortunate you didn't do so in post #1.

This is not a ping faillure. This is a name resolution failure.

You need to put the name&IP into the Win7 hosts file.
http://social.technet.microsoft.com/...4-3b5b3f02a1ae

[clariceoshea]

just one iddy biddy problem with the hosts file

my Cable ISP uses DHCP so the IP address changes frequently

[stevea]

So how does the Linux system resolve the other's IP address ?

What does
nslookup landonkelsey-PC
nslookup Precision-380
return Post all in a quote) ? What is in the Linux /etc/hosts ?

[clariceoshea]

landon@Precision-380 etc]$ nslookup landonkelsey-PC
Server: 192.168.123.254
Address: 192.168.123.254#53

Non-authoritative answer:
Name: landonkelsey-PC
Address: 8.15.7.122
Name: landonkelsey-PC
Address: 63.251.179.29

[landon@Precision-380 etc]$ nslookup Precision-380
Server: 192.168.123.254
Address: 192.168.123.254#53

Non-authoritative answer:
Name: Precision-380
Address: 50.57.197.175
Name: Precision-380
Address: 69.16.143.85
Name: Precision-380
Address: 66.152.109.85

[landon@Precision-380 etc]$ ifconfig
lo: flags=73<UP,LOOPBACK,RUNNING> mtu 16436
inet 127.0.0.1 netmask 255.0.0.0
inet6 ::1 prefixlen 128 scopeid 0x10<host>
loop txqueuelen 0 (Local Loopback)
RX packets 6 bytes 520 (520.0 B)
RX errors 0 dropped 0 overruns 0 frame 0
TX packets 6 bytes 520 (520.0 B)
TX errors 0 dropped 0 overruns 0 carrier 0 collisions 0

p4p1: flags=4163<UP,BROADCAST,RUNNING,MULTICAST> mtu 1500
inet 192.168.123.100 netmask 255.255.255.0 broadcast 192.168.123.255
inet6 fe80::213:72ff:fe21:cf41 prefixlen 64 scopeid 0x20<link>
ether 00:13:72:21:cf:41 txqueuelen 1000 (Ethernet)
RX packets 36665 bytes 48720049 (46.4 MiB)
RX errors 0 dropped 0 overruns 0 frame 0
TX packets 25505 bytes 3316205 (3.1 MiB)
TX errors 0 dropped 0 overruns 0 carrier 0 collisions 0
device interrupt 17

[landon@Precision-380 etc]$ cat /etc/hosts.............did this last week..didn't work
192.168.123.101 Precision-380
127.0.0.1 localhost localhost.localdomain localhost4 localhost4.localdomain4
::1 localhost localhost.localdomain localhost6 localhost6.localdomain6
[landon@Precision-380 etc]$

when I tried to wrap message in quotes, got message "message too short"

[jpollard]

You have the wrong IP number:

From the ifconfig on the Precision-380 the IP number is 192.168.123.100.

From the hosts file you have "192.168.123.101 Precision-380"

From the nslookup you get three different IP numbers, none of which is 192.168.123.x

So, no things are not going to work until you get all three to agree.

[clariceoshea]

I'm back

both hosts files have :

192.168.123.101 landon-PC
192.168.123.100 Precision-380

both pings work either direction,,,thank you

NOW what happens when the cable ISP changes my IP address since I have no static IP

Are these host file going to be automatically updated

don't think so

also:

this failed even after reboot

[landon@Precision-380 ~]$ rcp landon-PC:/home/landon/.bashrc .
landon-PC: No route to host
[landon@Precision-380 ~]$

[DBelton]

Your cable ISP doesn't control the IP address on your local network. All it changes is your WAN side (outward facing IP side) IP address. Now you cable modem/router is probably acting as a DHCP server, and assigning the network addresses of your computer, but that is completely different from what your ISP assigns.

You could set all of your computers to use static IP addresses, or if your cable modem/router can do it, have it assign a specific network address for a particular machine.

[hmmsjan]

Dear clariceoshea,

I've really no clue at all what your DNS server is doing, is it giving some complete random addresses?
Your network is within the range 192.168.123.1 to 192.168.123.254, and the addresses nslookup gives are outside your network and seem to have no relation to each other. Is'nt your cable modem broken/buggy?

Practically: Assuming that your modem is at 192.168.123.254 and stays there:
enter .100 and .101 as fixed IP's, default gateway is 192.168.123.254, DNS server the same or the providers upstream server,
name and IP in the hosts files and happy networking..... For a small network not that problem.....


Kind regards,

[jpollard]

The name server (at 192.168.123.254) is doing exactly what it is supposed to.

The three IP numbers provided are the public IP numbers used by remote users to connect to the router. The only issue I see is that the name server doesn't have the proper domain (hwng.net doesn't allow tracing any further, and doesn't allow reverse lookup), otherwise the returned IP numbers would include the associated domain.

Using the hosts table bypasses DNS anyway (as long as you have a sane /etc/nsswitch.conf file that puts files before dns).

After that, the IP number assigned to the interface is set either by DHCP (if enabled), or static assignment from the network configuration files (/etc/sysconfig/network-scripts/ifcfg-<interface-name>).

The IP numbers between the /etc/hosts file and the configuration scripts should agree.