(Ethernet -- WiFi -- Printer) Problem, routing or bridging fails.

Question

Hello. I have 2 computers and a printer.
computer[192.168.100.2] is running MacOSX and has an ethernet card
computer[192.168.100.3] is running ArchLinux 2.6.31 and has 2 interfaces: eth0 - ethernet and wlan0 is wireless (Marvell 99w9335 Libertas, uses ndiswrapper)
printer[192.168.100.17] is running an unknown OS and links via wifi
adsl router[192.168.100.1] has 4 ethernet ports, it acts here like a switch
I need to print from the computer[192.168.100.2]:
computer[100.2]{en0}  <--adsl router-->  {eth0}computer[100.3]{wlan0}  <-->  {wifi}printer[100.17]
I tried two methods:
1)routing
2)bridging
1)
modprobe ndiswrapper
iwconfig wlan0 mode Ad-Hoc essid "my_adhoc" channel 6
ifconfig wlan0 192.168.100.3 up
route add 192.168.100.17 wlan0
iptables -t nat -A POSTROUTING -o wlan0 -j MASQUERADE
echo 1 > /proc/sys/net/ipv4/ip_forward
/etc/rc.d/iptables save
/etc/rc.d/iptables start
After adding a route to 192.168.100.17 in MacOSX I can ping the printer and access printer's web site.
But I can't print, probably because it uses some specific tcp ports (9100,9101,9102,9110,9220) and may be udp ports, which I can't access.
May be I need something like: iptables --append FORWARD --in-interface eth0 -j ACCEPT
2)
modprobe ndiswrapper
iwconfig wlan0 mode Ad-Hoc essid "my_adhoc" channel 6
ifconfig wlan0 192.168.100.3 up
brctl addbr mybridge
brctl addif mybridge eth0
brctl addif mybridge wlan0
ifconfig eth0 0.0.0.0 promisc up
ifconfig wlan0 0.0.0.0 promisc up
ifconfig mybridge 192.168.100.3 up
This variant looks more friendly and simple, but I can't here ping the printer from computer[100.2]. I noticed that when I try to ping from computer[100.2], printer receives the packets, but nothing returns to the sender.
Last edited by AleXoundOS (2010-05-02 20:12:29)

Answer 1

Thank you for replies.
In routed mode:
Setting wlan0 to other ip address(even in the same subnet) and adding "iptables -P FORWARD ACCEPT" plus reinstalling the printer in CUPS solved the problem in routed mode.
In bridge mode:
It is impossible to check whether the printer can ping hosts on my ethernet segment, because I don't know how to access it's OS (telnet and ssh don't work). The web site does not provide ping utility, just stats about packets transfers and wireless interface configuration. nmap shows:
80/tcp open http
9100/tcp open jetdirect
9101/tcp open jetdirect
9102/tcp open jetdirect
9110/tcp open unknown
9220/tcp open unknown
MAC Address: 00:25:B3:FD:A3:91 (Hewlett Packard)
Device type: printer
Running: HP embedded
OS details: HP Photosmart C4380, J6400-series, C7200-series, or D7260 printer
137/udp open|filtered netbios-ns
161/udp open|filtered snmp
427/udp open|filtered svrloc
3702/udp open|filtered unknown
5353/udp open|filtered zeroconf
9103/udp open|filtered unknown
32770/udp open|filtered sometimes-rpc4
32773/udp open|filtered sometimes-rpc10
MAC Address: 00:25:B3:FD:A3:91 (Hewlett Packard)
Device type: power-device|specialized|VoIP gateway|security-misc|printer|media device
Running: APC AOS 2.X|3.X, APC embedded, AudioCodes embedded, Bosch embedded, Digi NET+OS 7, HP embedded, Brother embedded, Motorola embedded
Last edited by AleXoundOS (2010-05-05 09:29:05)