ping without problem, can´t browse the web

[milhouse]

Hi,
I´ve got a very strange problem. I´m using Fedora Core 1.
I´ve DSL and a NAT router. Ping works fine but I can´t browse the web with any web browser (konqueror, opera, mozilla). I don´t think it´s a routing, name server problem or anything like that. All my network services (CVS, VNC, DHCP ...) work. I´ve removed the configuration for my network card and reconfigured it without success . Nevertheless here is my route output:

[milhouse@basra ~]$ route -n
Kernel IP Routentabelle
Ziel Router Genmask Flags Metric Ref Use Iface
192.168.123.0 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
0.0.0.0 192.168.123.254 0.0.0.0 UG 0 0 0 eth0
^
That´s my router ===|

Please help me as soon as possible.

THANX, milhouse

[Jman]

Ping works fine as in you can ping an outside address like fedoraforum.org? If so your network and DNS are up and it is a problem with web.

You are sure of the router IP?

Try temporarily disabling the firewall.

[milhouse]

Hi, thanks for your reply,
Yes, ping works fine for outside adresses (fedora-forum.org, not the stresstest (look forward)). I´m sure with the IP-adress of my router because I can access the web interface. I disabled firewall of FC1 because my router is a stealth firewall. I forgot to mention that in the past everything worked fine (web-browsing too) but I can´t remember what I did and why it don´t work fine anymore. On my windows box everything works. Any more ideas ?!?
For further information I´ve posted all outputs of commands concerning network I know but I can´t interpret them complete ...

[milhouse@basra ~]$ ifconfig
eth0 Protokoll:Ethernet Hardware Adresse 00:50:FC:B0:70:5B
inet Adresse:192.168.123.1 Bcast:192.168.123.255 Maske:255.255.255.0
UP BROADCAST RUNNING MULTICAST MTU:1500 Metric:1
RX packets:1293075 errors:0 dropped:0 overruns:0 frame:0
TX packets:2499878 errors:0 dropped:0 overruns:0 carrier:0
Kollisionen:0 Sendewarteschlangenlänge:1000
RX bytes:78090053 (74.4 Mb) TX bytes:3365050452 (3209.1 Mb)
Interrupt:11 Basisadresse:0xe400

lo Protokoll:Lokale Schleife
inet Adresse:127.0.0.1 Maske:255.0.0.0
UP LOOPBACK RUNNING MTU:16436 Metric:1
RX packets:210 errors:0 dropped:0 overruns:0 frame:0
TX packets:210 errors:0 dropped:0 overruns:0 carrier:0
Kollisionen:0 Sendewarteschlangenlänge:0
RX bytes:17506 (17.0 Kb) TX bytes:17506 (17.0 Kb)

[milhouse@basra ~]$ dmesg
[...]
eth0: RealTek RTL8139 Fast Ethernet at 0xe400, 00:50:fc:b0:70:5b, IRQ 11
eth0: Identified 8139 chip type 'RTL-8100B/8139D'
ip_tables: (C) 2000-2002 Netfilter core team
eth0: link up, 100Mbps, full-duplex, lpa 0x45E1


[root@basra /home/milhouse]# mii-tool -v
eth0: negotiated 100baseTx-FD, link ok
product info: vendor 00:00:00, model 0 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 flow-control


Stresstest (!22% packets loss! perhaps this is the reason => but how can I fix it.) ...

[root@basra /home/milhouse]# ping -s 512 -c 400 -f -n www.google.de
PING www.google.akadns.net (216.239.59.99) 512(540) bytes of data.
.
--- www.google.akadns.net ping statistics ---
400 packets transmitted, 310 received, 22% packet loss, time 6025ms
rtt min/avg/max/mdev = 128.609/3227.568/6286.124/1784.155 ms, pipe 231, ipg/ewma 15.102/6147.730 ms


[root@basra /home/milhouse]# ping fedoraforum.org
PING fedoraforum.org (64.46.100.35) 56(84) bytes of data.
64 bytes from mail.ewdi.org (64.46.100.35): icmp_seq=0 ttl=43 time=193 ms
64 bytes from mail.ewdi.org (64.46.100.35): icmp_seq=1 ttl=43 time=192 ms
64 bytes from mail.ewdi.org (64.46.100.35): icmp_seq=2 ttl=43 time=194 ms
64 bytes from mail.ewdi.org (64.46.100.35): icmp_seq=3 ttl=43 time=191 ms
64 bytes from mail.ewdi.org (64.46.100.35): icmp_seq=4 ttl=43 time=194 ms

--- fedoraforum.org ping statistics ---
5 packets transmitted, 5 received, 0% packet loss, time 4041ms
rtt min/avg/max/mdev = 191.734/193.358/194.963/1.241 ms, pipe 2

Greetz, milhouse

[JTM_88]

I am having the same problem.
I can ping sites and not browse them.
It happened after I did some editting of iptables in my /rc.local file at startup. I also upped the security level of my DSL modem/hardware firewall.
Even more wierd, my NAT client computers that are using my Fedora Core 2 NAT server can browse and access the internet just fine.
I don't think it's the DSL modem/hardware firewall because I think my NAT clients would have the same problem as my server.
So I'm certain it is something to do with my iptables setup. I'll reply when I have an answer.

[JTM_88]

Okay, the problem and solution is pretty simple.

Problem:
No rules about handling network output.
You can check this by doing
$ iptables --list
or, a more thorough listing is
$ /etc/init.d/iptables status

if your OUTPUT chain has no rules in it then the following is your solution.

Simple Fix:
$ iptables -A OUTPUT -j ACCEPT

This fix is not security conscious.
You should check out http://www.siliconvalleyccie.com/lin...bles-intro.htm
for more info on iptables. btw, this site has some really good tutorials on Linux with consideration of Fedora Core 2. If you find it useful, you should donate $5

Good luck.