now I network.... now I don't.....

**alondro** · 06-10-2009, 03:06 PM

Hello,
My first post. I run a small centre for village kids in India. I have two computers with fedora 9. I decided to try and run edubuntu on my old IBM P3 but ran into installation problems.. so I decided to reinstall Fedora 9. But since then I have not been able to network the two computers.

1. I connect to internet through comp 1 via gprs and this is shared with comp 2 .

2. Both have static IPs. comp 1 ip 192.168.10.1, which is also the gateway for comp 2 whose ip is 192.168.10.2

3. They are not able to ping each other except if I give the command 'service network restart' when they ping each other for about 30 seconds and then stops pinging?????

If it was a hardware problem then they would not ping even for 30 secs.... seems I am missing something.

Before I tried Edubuntu I had a good network and could share the internet between the two and now they don't even want to talk to each other Boooo.....

**peter** · 06-11-2009, 04:45 AM

Do you have any other machine on your network doing proxy ARP? Does the ARP shown on the interfaces match the listings on all machines when you use the

Code:

arp -a

command?

It sounds like more than one machine on the network may have the same IP address.

**alondro** · 06-11-2009, 03:21 PM

[QUOTE=peter;140888]Do you have any other machine on your network doing proxy ARP? Does the ARP shown on the interfaces match the listings on all machines when you use the

Code:

arp -a

command?

Thanks for your reply Peter.... gives me hope of finding some guidance

But when I give the arp -a command it shows nothing...

and I have a very small network of just two computers connected through a crossover cable. I have tried changing the IP's of the computers A/B from 192.168.10.1 /2 to 192.168.1.10 /20 for them respectively Netmask 255.255.255.0 but to no effect.

What I do not understand is why they ping each other when I do a 'service network restart' for 30 secs and then it stops.

Does that mean some other service starts in the meantime which cuts the LAN off..??

Alok

**peter** · 06-12-2009, 01:45 PM

What does the /var/log/messages file say when this happens? The site has a section on troubleshooting with syslog.

**alondro** · 06-12-2009, 03:23 PM

Thanks Peter but I will not be in front of those computers till monday and will give you the details as soon as I reach back.

Alok

**alondro** · 06-16-2009, 11:57 AM

Do you want me to post you the results for both the computers.... I still am not able to figure this out and I am also trying to go through the guides posted by you... still I need more help..
Thanks

**alondro** · 06-16-2009, 11:58 AM

Originally Posted by peter

Do you have any other machine on your network doing proxy ARP? Does the ARP shown on the interfaces match the listings on all machines when you use the

Code:

arp -a

command?

It sounds like more than one machine on the network may have the same IP address.

Hi Peter,
Here is the output of some of the commands given on the computer 2 after a Service network restart on computer 1 (which is supposed to be the server).
[root@tirk ~]# ethtool eth0
Settings for eth0:
No data available
[root@tirk ~]# arp -a
? (192.168.1.10) at 00:E0:18:FC:14:FF [ether] on eth0
[root@tirk ~]# mii-tool eth0
eth0: negotiated 100baseTx-FD, link ok
[root@tirk ~]# ping 192.168.1.10
PING 192.168.1.10 (192.168.1.10) 56(84) bytes of data.
64 bytes from 192.168.1.10: icmp_seq=1 ttl=64 time=1.29 ms
64 bytes from 192.168.1.10: icmp_seq=2 ttl=64 time=0.288 ms
64 bytes from 192.168.1.10: icmp_seq=3 ttl=64 time=0.287 ms
64 bytes from 192.168.1.10: icmp_seq=4 ttl=64 time=0.282 ms
64 bytes from 192.168.1.10: icmp_seq=5 ttl=64 time=0.287 ms
64 bytes from 192.168.1.10: icmp_seq=6 ttl=64 time=0.283 ms
^C
--- 192.168.1.10 ping statistics ---
6 packets transmitted, 6 received, 0% packet loss, time 5701ms
rtt min/avg/max/mdev = 0.282/0.453/1.293/0.375 ms
[root@tirk ~]# cat /proc/interrupts
CPU0
0: 178 XT-PIC-XT timer
1: 1282 XT-PIC-XT i8042
2: 0 XT-PIC-XT cascade
4: 4 XT-PIC-XT
6: 3 XT-PIC-XT floppy
7: 1 XT-PIC-XT parport0
8: 0 XT-PIC-XT rtc0
9: 509 XT-PIC-XT acpi, Intel 82801AA-ICH
10: 1 XT-PIC-XT uhci_hcd:usb1
11: 466 XT-PIC-XT eth0
12: 8574 XT-PIC-XT i8042
14: 8111 XT-PIC-XT ata_piix
15: 1672 XT-PIC-XT ata_piix
NMI: 0 Non-maskable interrupts
LOC: 127657 Local timer interrupts
RES: 0 Rescheduling interrupts
CAL: 0 function call interrupts
TLB: 0 TLB shootdowns
TRM: 0 Thermal event interrupts
SPU: 0 Spurious interrupts
ERR: 0
MIS: 0
[root@tirk ~]# cat /etc/sysconfig/network-scripts/ifcfg-eth0
# Davicom Semiconductor, Inc. 21x4x DEC-Tulip compatible 10/100 Ethernet
DEVICE=eth0
BOOTPROTO=none
HWADDR=00:80:ad:83:5f:a5
ONBOOT=yes
NM_CONTROLLED=no
NETMASK=255.255.255.0
IPADDR=192.168.1.11
TYPE=Ethernet
USERCTL=yes
PEERDNS=no
IPV6INIT=no
GATEWAY=192.168.1.10
BROADCAST=192.168.1.255
NETWORK=192.168.1.0
[root@tirk ~]# ping 192.168.1.10
PING 192.168.1.10 (192.168.1.10) 56(84) bytes of data.
From 192.168.1.11 icmp_seq=10 Destination Host Unreachable
From 192.168.1.11 icmp_seq=11 Destination Host Unreachable
From 192.168.1.11 icmp_seq=12 Destination Host Unreachable
^C
--- 192.168.1.10 ping statistics ---
14 packets transmitted, 0 received, +3 errors, 100% packet loss, time 13407ms
pipe 3
[root@tirk ~]# mii-tool eth0
eth0: negotiated 100baseTx-FD, link ok
[root@tirk ~]# arp -a
? (192.168.1.10) at <incomplete> on eth0
[root@tirk ~]# mii-tool eth0
eth0: negotiated 100baseTx-FD, link ok
[root@tirk ~]# ethtool eth0
Settings for eth0:
No data available
[root@tirk ~]# ethtool -S eth0
no stats available
[root@tirk ~]# route
Kernel IP routing table
Destination Gateway Genmask Flags Metric Ref Use Iface
192.168.1.0 * 255.255.255.0 U 0 0 0 eth0
link-local * 255.255.0.0 U 0 0 0 eth0
default 192.168.1.10 0.0.0.0 UG 0 0 0 eth0
[root@tirk ~]# ifconfig
eth0 Link encap:Ethernet HWaddr 00:80:AD:83:5F:A5
inet addr:192.168.1.11 Bcast:192.168.1.255 Mask:255.255.255.0
inet6 addr: fe80::280:adff:fe83:5fa5/64 Scope:Link
UP BROADCAST MULTICAST MTU:1500 Metric:1
RX packets:167 errors:137 dropped:0 overruns:0 frame:0
TX packets:100 errors:5 dropped:0 overruns:0 carrier:5
collisions:0 txqueuelen:1000
RX bytes:21553 (21.0 KiB) TX bytes:10755 (10.5 KiB)
Interrupt:11 Base address:0xf00

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:2430 errors:0 dropped:0 overruns:0 frame:0
TX packets:2430 errors:0 dropped:0 overruns:0 carrier:0
collisions:0 txqueuelen:0
RX bytes:126676 (123.7 KiB) TX bytes:126676 (123.7 KiB)
[root@tirk ~]# netstat -i Kernel Interface table Iface MTU Met RX-OK RX-ERR RX-DRP RX-OVR TX-OK TX-ERR TX-DRP TX-OVR Flg eth0 1500 0 167 550 0 0 100 5 0 0 BMU lo 16436 0 2903 0 0 0 2903 0 0 0 LRU [root@tirk ~]# mii-tool -v eth0: negotiated 100baseTx-FD, link ok product info: vendor 00:60:6e, model 4 rev 0 basic mode: autonegotiation enabled basic status: autonegotiation complete, link ok capabilities: 100baseTx-FD 100baseTx-HD 10baseT-FD 10baseT-HD advertising: 100baseTx-FD 100baseTx-HD 10baseT-FD 10baseT-HD link partner: 100baseTx-FD 100baseTx-HD 10baseT-FD 10baseT-HD

Here if you noticed that the two computers were able to ping in the beginning when I had given the Service network restart command on Computer 1 and then it was lost somewhere after 30 secs..........??
Thanks

Alok

**alondro** · 06-17-2009, 06:01 AM

[QUOTE
[root@tirk ~]# ifconfig
eth0 Link encap:Ethernet HWaddr 00:80:AD:83:5F:A5
inet addr:192.168.1.11 Bcast:192.168.1.255 Mask:255.255.255.0
inet6 addr: fe80::280:adff:fe83:5fa5/64 Scope:Link
UP BROADCAST MULTICAST MTU:1500 Metric:1
RX packets:167 errors:137 dropped:0 overruns:0 frame:0
TX packets:100 errors:5 dropped:0 overruns:0 carrier:5
collisions:0 txqueuelen:1000
RX bytes:21553 (21.0 KiB) TX bytes:10755 (10.5 KiB)
Interrupt:11 Base address:0xf00

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:2430 errors:0 dropped:0 overruns:0 frame:0
TX packets:2430 errors:0 dropped:0 overruns:0 carrier:0
collisions:0 txqueuelen:0
[/QUOTE]

Hi Peter,

I just noticed that the ifconfig command on the comp 2 is missing the word RUNNING in UP BROADCAST MULTICAST..... But when it is able to ping then it shows RUNNING also... what does that mean
Alok

**peter** · 06-18-2009, 02:21 AM

You have given your interface the IP address reserved for broadcast messages. Your last octet cannot be 255 with that subnet mask. It needs to be in range of .1 to .254.