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I just installed Fedora core 5 on a home PC machine (double-boots WinXP & Fedora) beneath a DSL gateway running DHCP. Just about everything remains in its default configuration. The network works fine on the WinXP side, but only connects with a few sites under Fedora. Yum, downloads, and google always fail. Experimenting, I found that wget to a particular site only works if I first perform an nslookup to it. I can ping my ISP's DNS server and the DSL router, the router's lights are all green. Traceroute shows nothing but asterisks. I stopped iptables temporarily, but got the same behavior. Some relevant command output follows.
What could cause this? What should I check next?
NOTE: I had to edit out the URLs below in order to get
this post to work. Various URLs that I've tried
show the same behavior.
------------- mii-tool -v ----------------
eth0: negotiated 100baseTx-FD flow-control, link ok
product info: vendor 00:07:49, model 1 rev 1
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 flow-control
link partner: 100baseTx-FD 100baseTx-HD 10baseT-FD 10baseT-HD flow-control
-------- ethtool eth01 ---------
Settings for eth0:
No data available
--------- ifconfig -a --------------
eth0 Link encap:Ethernet HWaddr 00:0C:41:EF:33:70
inet addr:192.168.0.2 Bcast:192.168.0.255 Mask:255.255.255.0
inet6 addr: fe80::20c:41ff:feef:3370/64 Scope:Link
UP BROADCAST RUNNING MULTICAST MTU:1500 Metric:1
RX packets:5 errors:0 dropped:0 overruns:0 frame:0
TX packets:27 errors:0 dropped:0 overruns:0 carrier:0
RX bytes:955 (955.0 b) TX bytes:3557 (3.4 KiB)
Interrupt:9 Base address:0x6000
sit0 Link encap:IPv6-in-IPv4
NOARP MTU:1480 Metric:1
RX packets:0 errors:0 dropped:0 overruns:0 frame:0
TX packets:0 errors:0 dropped:0 overruns:0 carrier:0
RX bytes:0 (0.0 b) TX bytes:0 (0.0 b)
-----------wget URL-WAS-HERE ------------ wget fails
Resolving URL-WAS-HERE... 184.108.40.206
Connecting to URL-WAS-HERE|220.127.116.11|:80...
-----------/sbin/arp -a ----------- shows contact with gateway DSL router
dslmodem.domain.actdsltmp (192.168.0.1) at 00:15:05:0C:0F:8A [ether] on eth0
----------ping 18.104.22.168 # ISP's DNS server----------
PING 22.214.171.124 (126.96.36.199) 56(84) bytes of data.
64 bytes from 188.8.131.52: icmp_seq=1 ttl=62 time=31.0 ms
64 bytes from 184.108.40.206: icmp_seq=2 ttl=62 time=32.0 ms
64 bytes from 220.127.116.11: icmp_seq=3 ttl=62 time=30.8 ms
64 bytes from 18.104.22.168: icmp_seq=4 ttl=62 time=53.0 ms
64 bytes from 22.214.171.124: icmp_seq=5 ttl=62 time=31.8 ms
64 bytes from 126.96.36.199: icmp_seq=6 ttl=62 time=31.6 ms
--- 188.8.131.52 ping statistics ---
6 packets transmitted, 6 received, 0% packet loss, time 5002ms
rtt min/avg/max/mdev = 30.842/35.089/53.061/8.051 ms
I fixed the problem described above, only to have it return each
time that I reboot. It appears to be a DHCP problem that shows up
in both Fedora and Ubuntu. My PC is connected to an ISP via an
Actiontec DSL modem. By default, whenever I boot, the /etc/resolv.conf
file gets replaced with the following:
; generated by /sbin/dhclient-script
The first IP address shown is that of the DSL router, which
should not be in the list. If I correct the file to:
then the Internet connection works fine, until I reboot. What's the
best way for me to fix this problem?
This prepends the known servers to the list, so if they are found
all is well. The drawback is that if my ISP changes its DNS servers,
then DNS will hang on the bogus entry before reaching the new real
servers... the same behavior that I saw before. Actually fixing the
problem will involve looking at how dhclient is working, which I'm
not prepared to get into right now.
If anyone knows of a better solution, I'm all ears. :-)