LinuxQuestions.org
Review your favorite Linux distribution.
Go Back   LinuxQuestions.org > Forums > Linux Forums > Linux - Networking
User Name
Password
Linux - Networking This forum is for any issue related to networks or networking.
Routing, network cards, OSI, etc. Anything is fair game.

Notices

Reply
 
Search this Thread
Old 10-30-2004, 11:15 AM   #1
djkadu
LQ Newbie
 
Registered: Oct 2004
Location: London
Distribution: Debian woody
Posts: 4

Rep: Reputation: 0
Gateway works fine but i can't ping from it.


Hi, I'm using a debian woody box as my gateway at home, It has a network card for the local network (eth0) and a internal ADSL card for the internet connection (ppp0)

Everything was forking fine for the 2 years untill a few months ago someting happend.
The gateway still working fine and I can full access to the internet from any computer on the network, except fom it. I mean, if I log in to it (SSH2) I can't PING anything, on the local network or on the internet, even using the IP addreses.
i'm not an expert in linux, but i've been using it for a few years. I think is something related to the routes, but I don't know nothing about it.
So here is the output of my route command:

xavier:~# route
Kernel IP routing table
Destination Gateway Genmask Flags Metric Ref Use Iface
62.241.161.247 * 255.255.255.255 UH 0 0 0 ppp0
localnet * 255.255.255.0 U 0 0 0 eth0
default 62.241.161.247 0.0.0.0 UG 0 0 0 ppp0

and this is my ifconfig:

xavier:~# ifconfig
eth0 Link encap:Ethernet HWaddr 00:E0:18:20:06:93
inet addr:192.168.100.100 Bcast:192.168.100.255 Mask:255.255.255.0
inet6 addr: fe80::2e0:18ff:fe20:693/10 Scope:Link
UP BROADCAST RUNNING MULTICAST MTU:1500 Metric:1
RX packets:124706398 errors:0 dropped:0 overruns:0 frame:0
TX packets:132292627 errors:3 dropped:0 overruns:0 carrier:3
collisions:0 txqueuelen:100
RX bytes:3095407628 (2.8 GiB) TX bytes:1083118492 (1.0 GiB)
Interrupt:5 Base address:0xb800 Memory:e1800000-e1800038

imq0 Link encap:UNSPEC HWaddr 00-00-00-00-00-00-00-00-00-00-00-00-00-00-00-00
UP RUNNING NOARP MTU:1500 Metric:1
RX packets:137482763 errors:0 dropped:0 overruns:0 frame:0
TX packets:137482763 errors:0 dropped:0 overruns:0 carrier:0
collisions:0 txqueuelen:30
RX bytes:2751651323 (2.5 GiB) TX bytes:2751651323 (2.5 GiB)

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:356 errors:0 dropped:0 overruns:0 frame:0
TX packets:356 errors:0 dropped:0 overruns:0 carrier:0
collisions:0 txqueuelen:0
RX bytes:23354 (22.8 KiB) TX bytes:23354 (22.8 KiB)

ppp0 Link encap:Point-to-Point Protocol
inet addr:*.*.*.* P-t-P:62.241.161.247 Mask:255.255.255.255
UP POINTOPOINT RUNNING NOARP MULTICAST MTU:1300 Metric:1
RX packets:69850422 errors:0 dropped:0 overruns:0 frame:0
TX packets:63021821 errors:0 dropped:0 overruns:0 carrier:0
collisions:0 txqueuelen:60
RX bytes:3496095464 (3.2 GiB) TX bytes:4061874683 (3.7 GiB)

the imq0 is there becous I use a network shaper script for the ADSL connection.

Well, if you need any more information please ask, Any help is very appreciated.
thanks
Kadu
 
Old 10-30-2004, 11:30 AM   #2
Mara
Moderator
 
Registered: Feb 2002
Location: Grenoble
Distribution: Debian
Posts: 9,537

Rep: Reputation: 149Reputation: 149
Routing table looks OK. It may be something with firewall (you have NAT/masquerade, I think) or the shaper.
 
Old 10-30-2004, 02:59 PM   #3
djkadu
LQ Newbie
 
Registered: Oct 2004
Location: London
Distribution: Debian woody
Posts: 4

Original Poster
Rep: Reputation: 0
OK, that's a beggining.
I already deactivated the script and i'm using iptables i beleive

xavier:~# iptables -L
Chain INPUT (policy DROP)
target prot opt source destination
UNCLEAN all -- anywhere anywhere unclean
ACCEPT all -- anywhere anywhere
LD all -- anywhere anywhere state INVALID
ACCEPT all -- localnet/24 anywhere
LD all -- 224.0.0.0/8 anywhere
LD all -- anywhere 224.0.0.0/8
LD all -- 255.255.255.255 anywhere
LD all -- anywhere 0.0.0.0
LD all -- anywhere anywhere state INVALID
ACCEPT tcp -- anywhere anywhere tcp dpts:bootps:bootpc
ACCEPT udp -- anywhere anywhere udp dpts:bootps:bootpc
ACCEPT tcp -- anywhere anywhere tcp dpts:netbios-ns:netbios-ssn
ACCEPT udp -- anywhere anywhere udp dpts:netbios-ns:netbios-ssn
ACCEPT tcp -- anywhere anywhere tcp dpt:445
ACCEPT udp -- anywhere anywhere udp dpt:445
ACCEPT tcp -- anywhere anywhere tcp dpt:2049
ACCEPT udp -- anywhere anywhere udp dpt:2049
LD tcp -- anywhere anywhere tcp dpts:x11:6015
LD udp -- anywhere anywhere udp dpts:x11:6015
ACCEPT tcp -- anywhere anywhere tcp dpts:bootps:bootpc
ACCEPT udp -- anywhere anywhere udp dpts:bootps:bootpc
LD tcp -- anywhere anywhere tcp dpt:5000
LD udp -- anywhere anywhere udp dpt:5000
LD tcp -- anywhere anywhere tcp flags:!SYN,RST,ACK/SYN state NEW
ACCEPT tcp -- anywhere anywhere tcp spt:ssh dpts:login:65535 flags:!SYN,RST,ACK/SYN state RELATED
ACCEPT tcp -- anywhere anywhere tcp spt:ftp-data dpts:1023:65535 flags:!SYN,RST,ACK/SYN state RELATED
LD all -- anywhere anywhere
ACCEPT udp -- anywhere anywhere udp dpt:6699
ACCEPT udp -- anywhere anywhere udp dpt:6699
ACCEPT tcp -- anywhere anywhere tcp dpt:6699

Chain FORWARD (policy DROP)
target prot opt source destination
UNCLEAN all -- anywhere anywhere unclean
ACCEPT tcp -- anywhere 192.168.100.110 tcp dpt:3389
ACCEPT all -- localnet/24 anywhere
ACCEPT all -- anywhere localnet/24

Chain OUTPUT (policy DROP)
target prot opt source destination
UNCLEAN all -- anywhere anywhere unclean
ACCEPT all -- anywhere anywhere
ACCEPT all -- localnet/24 anywhere
ACCEPT icmp -- localnet/24 anywhere
LD all -- 224.0.0.0/8 anywhere
LD all -- anywhere 224.0.0.0/8
LD all -- 255.255.255.255 anywhere
LD all -- anywhere 0.0.0.0
DROP tcp -- anywhere anywhere tcp flags:!SYN,RST,ACK/SYN state NEW
all -- anywhere anywhere TTL match TTL == 64
ACCEPT all -- anywhere anywhere
ACCEPT udp -- anywhere anywhere udp spt:6699
ACCEPT udp -- anywhere anywhere udp spt:6699
ACCEPT tcp -- anywhere anywhere tcp dpt:6699

Chain LD (19 references)
target prot opt source destination
LOG all -- anywhere anywhere LOG level warning
DROP all -- anywhere anywhere

Chain SANITY (0 references)
target prot opt source destination
LD all -- anywhere anywhere

Chain STATE (0 references)
target prot opt source destination
ACCEPT all -- anywhere anywhere state RELATED,ESTABLISHED
ACCEPT all -- anywhere anywhere state NEW
LD all -- anywhere anywhere

Chain UNCLEAN (3 references)
target prot opt source destination
LD all -- anywhere anywhere
 
Old 10-31-2004, 09:49 AM   #4
Mara
Moderator
 
Registered: Feb 2002
Location: Grenoble
Distribution: Debian
Posts: 9,537

Rep: Reputation: 149Reputation: 149
Iptables, definitely Unfortunately I have problems reading the output (iptables -L). I'm interested in the part of the script dealing with OUTPUT chain. If it's not too long, please copy it.
 
Old 10-31-2004, 12:31 PM   #5
ugge
Senior Member
 
Registered: Dec 2000
Location: Gothenburg, SWEDEN
Distribution: OpenSUSE 10.3
Posts: 1,028

Rep: Reputation: 45
According to this listing it seems as though your firewall lets just about anything through, except for malformed packets.
To have a closer look at the fancy settings it would nice with a listing from
Code:
iptables -n -v -L
 
  


Reply


Thread Tools Search this Thread
Search this Thread:

Advanced Search

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is Off
HTML code is Off


Similar Threads
Thread Thread Starter Forum Replies Last Post
can't ping localhost, Internet works fine drowstar Linux - Networking 5 01-04-2005 03:09 PM
PPP establish can ping the gateway router but unable to ping the host deepalalla Linux - Networking 0 11-18-2004 09:10 AM
dhcp client can't ping gateway but can ping other local hosts dirty_forks Linux - Networking 7 10-08-2004 10:54 AM
No internet, but pings gateway fine nateinabox Linux - Networking 40 08-07-2003 07:04 PM
3c509 cant ping out - others ping it fine! chosmer Linux - Newbie 1 03-04-2002 04:56 PM


All times are GMT -5. The time now is 08:33 AM.

Main Menu
My LQ
Write for LQ
LinuxQuestions.org is looking for people interested in writing Editorials, Articles, Reviews, and more. If you'd like to contribute content, let us know.
Main Menu
Syndicate
RSS1  Latest Threads
RSS1  LQ News
Twitter: @linuxquestions
identi.ca: @linuxquestions
Facebook: linuxquestions Google+: linuxquestions
Open Source Consulting | Domain Registration