SDB:Instructions to solve network problems
Request:
The network functionality is not available.
Procedure:
Check first, if the network device, the network card is recognized by the kernel. Correct function can be proven by looking into /var/log/messages
which can be scanned to the keywords
-
eth0
for Ethernet netzwerk cards, -
sdla
for Frame relay devices -
atp
for parallel port adapter -
arc
für arcnet devices -
plip
for parallel port devices -
slip_proto
for Slip interfaces to boot -
mkiss_proto
for KISS (AX25) -
strip_proto
for Starmode Radio IP -
ppp_prot
for PPP protocoll -
dummy
for das dummy device -
eql
for Line Balancing -
tr
for Token Ring -
fddi
for FDDI -
tunl
for Tunnel device -
bif
-
lo
for loopback device -
isdn
for ISDN device (Raw IP) -
ippp
for ISDN device (IP over PPP on ISDN) -
ppp
for PPP
depending on the type of network device or network card.
If the support of the device is realized as module, the file /etc/conf.modules
must be checked, whether the parameters included herein, especially ports, interrupts, memory, interface conform with the real world.
A typical entry looks like
# Aliases - specify your hardware alias eth0 tulip
und weiter unten
options tulip options=0
Additionally, the loading operations of modules must be checked using command lsmod
.
If a module or a kernel built in device has been found according to /var/log/messages
, the configuration can be checked by the command ifconfig
A typical result screen looks like
eth0 Link encap:10Mbps Ethernet HWaddr 00:40:05:41:4C:51 inet addr:192.168.1.1 Bcast:192.168.1.255 Mask:255.255.255.0 UP BROADCAST RUNNING MULTICAST MTU:1500 Metric:1 RX packets:22369990 errors:0 dropped:0 overruns:0 TX packets:13964874 errors:2514 dropped:0 overruns:0 Interrupt:9 Base address:0x6100
It is important, that cards with a real hardware address (Ethernet, Arcnet, FDDI) display a real HWaddr, not 00:00:00:00:00:00 or ff:ff:ff:ff:ff:ff. The IP address is assigned by YaST.
If the module cannot be loaded, or the kernel bound in driver cannot access the device, checks should be done:
- Is the appropriate driver in use? (e.g. the modern ne-driver is not suitable for PCI-ne-cards.
- Is a more recent driver available for the device? It should be used. If necessary, it should be downloaded, see hints at the end of the article.
- Is the card, the interface physically present?
- Is the card, the interface configured correctly concerning interrupt, i/o-port, shared memory and DMA channel? If necessary, Linux or DOS programs must be used for configuration.
- Do hardware conflicts exist?
- With ISA cards, interrupt, i/o port, shared memory and DMA channel must be proven. In case of ISA cards with shared memory areas, the BIOS must free that area, if necessary the range must be passed to the kernel, interrupt, DMA and i/o conflicts have to be removed by reconfiguring the involved cards.
- With PCI cards mainly interrupt conflicts occur. In the case of interrupt conflicts, checks have to be done on
- the driver permits interrupt sharing
- permutating the PCI cards into other PCI slots the interrupt assignment can be changed.
- the BIOS assignment can be changed
- On network interface cards with multiple media interaces (10MB/s 10Base2, 10BaseTP and AUI) or several transceiving standards (10MB/s, 100MB/s) the choice of the correct medium is to be checked. For PCMCIA network cards there is a special Linux program, which allows hot switching.
- Faults in the transfer media have to be excluded. With more than two computers in the net, mutually connections should be built, the correct fitting and completeness of cabling must be proved, cable and auxiliary devices must be function proved.
If necessary the exchange of the card in doubt by a equal one and thereafter by a sample of completely different construction can be of great value to isolate the fault.
If the driver is loaded correctly, the interface eth0 can be configured by
ifconfig eth0 192.168.110.1 broadcast 192.168.110.255 netmask 255.255.255.0 up
for the IP address 192.168.110.1
. Thereafter, for test purposes a route can be set invoking
route add -net 192.168.110.0 netmask 255.255.255.0 eth0
Then the interface must be accessible by the command
ping 192.168.110.1
If the commands ifconfig
or route add
fail, conflicts in IP addresses, routes and interface names might have been occured. The described configurations by hand should only be done for testing purposes, if the canonical configuration with YaST does not succeed. The final configuration will be done naturally with YaST.
The most recent network card drivers are available from http://www.scyld.com/network/. Those drivers replace their predecessors in their suitable directory and the kernel must be recompiled and reinstalled, see manual!
SDB:Purpose and practical instruction to use IP addresses
SDB:ISA-PnP: Configuring an ISA-PnP card
<keyword>network,nic,networkcard,networkinterfacecard,slip,ppp,isdn</keyword>