Re: ARP Question - Maybe?

2003-09-28 Thread Drew Tomlinson
On Sat, 27 Sep 2003 16:55:35 +, Nathan Kinkade [EMAIL PROTECTED] 
wrote:

On Sat, Sep 27, 2003 at 03:31:16PM -0700, Drew Tomlinson wrote:
I'm trying to get a Linksys WET11 Wireless Ethernet Bridge working with 
a
D-Link 530 NIC that uses the rl driver.  I have configured the bridge 
and
gotten it to work with a Windows XP box if I tell the bridge to use MAC
address cloning.  However I can not get it working on my 4.8 FBSD box.

I'm not really sure but I suspect my problem might be with ARP?  The rl0
interface is configured as 192.168.100.2 and the bridge is connected to 
this
interface.  The bridge is configured with an IP address of 
192.168.100.225
but as I understand it, this is only the address to use when connecting 
to
the web based configuration utility. I have a Linksys access point with 
IP
of 192.168.100.1.

Anyway, after attempting connections to these three addresses, my arp 
table
looks like this:

? (192.168.100.1) at (incomplete) on rl0 [ethernet]
? (192.168.100.2) at 00:05:5d:d0:ba:67 on rl0 permanent [ethernet]
? (192.168.100.225) at (incomplete) on rl0 [ethernet]
I can not get any response from any device beyond the rl0 interface.  I
setup ipfw to log all traffic to that interface and can see the traffic
going out:
Sep 27 15:18:04 blacksheep /kernel: ipfw: 50 Accept ICMP:8.0 
192.168.100.2
192.168.100.1 out via rl0

Sep 27 15:24:00 blacksheep /kernel: ipfw: 50 Accept ICMP:8.0 
192.168.100.2
192.168.100.225 out via rl0

Can anyone educate me on arp and if it's my problem, tell me what I 
might
need to add to my arp table to get things going?

Thanks,

Drew
Thank you for your response.

I had this problem recently.  Turns out that ipfw when used in
conjunction with bridging (net.link.ether.bridge_ipfw=1) that your
I don't seem to have this.  I'm running 4.8.  Here's all of my net.link 
sysctls:

net.link.generic.system.ifcount: 8
net.link.ether.inet.prune_intvl: 300
net.link.ether.inet.max_age: 1200
net.link.ether.inet.host_down_time: 20
net.link.ether.inet.maxtries: 5
net.link.ether.inet.useloopback: 1
net.link.ether.inet.proxyall: 0
net.link.ether.inet.log_arp_wrong_iface: 1
net.link.ether.ipfw: 0
net.link.gif.max_nesting: 1
net.link.gif.parallel_tunnels: 0
default rule must be to allow all.  You can mitigate this by making your
last rule something like:
deny { tcp or udp } from any to any
I am already set up like this.

This should basically block pretty much any traffic that you are
probably worried about.  To test that this is the problem, disable the
firewall temporarily, maybe with something like:
# sysctl net.link.ether.bridge_ipfw=0

then try your network.  if it works, the re-enable ipfw by setting the
above parameter back to 1.  then take a look at your arp cache expiry
with `arp -an' and make note as to wether the net breaks again as soon
as the arp entry expires.
you can set ipfw to use a default rule of accepting by adding this
option to you kernel config:
options 	IPFIREWALL_DEFAULT_TO_ACCEPT
As I understand it, I don't need to configure my FBSD box as a bridge.  
Please let me know if I am incorrect.  Basically, I want to use my 
neighbor's connection as a backup link to the Internet.  He has a Linksys 
Wireless Access Point/Router in his home.  Instead of installing a 
wireless card in my FBSD box, I bought a Linksys Wireless Bridge so I 
could install it by a window to get a better signal.  The Linksys bridge 
connects via ethernet cable to the D-Link NIC in my FBSD box.  Here's a 
diagram of the setup:

Internet
|
Public IP
|
  ADSL Modem/Router
   192.168.10.1
|
   dc0
   192.168.10.2
|
FBSD 4.8 - rl0
| 192.168.100.2
   dc1  |
   192.168.1.2   192.168.100.225
| Wireless Bridge
   Internal LAN |
  192.168.100.1
  Neighbor's AP
I can get to the wireless bridge from my neighbor's network and I can get 
to the rl0 from my internal LAN.  The breakage is between the rl0 
interface and the linksys wireless bridge.  Do you have any idea what I 
need to configure to make things work?

Thanks again for your time!!!

Drew

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Re: ARP Question - Maybe?

2003-09-27 Thread Nathan Kinkade
On Sat, Sep 27, 2003 at 03:31:16PM -0700, Drew Tomlinson wrote:
 I'm trying to get a Linksys WET11 Wireless Ethernet Bridge working with a
 D-Link 530 NIC that uses the rl driver.  I have configured the bridge and
 gotten it to work with a Windows XP box if I tell the bridge to use MAC
 address cloning.  However I can not get it working on my 4.8 FBSD box.
 
 I'm not really sure but I suspect my problem might be with ARP?  The rl0
 interface is configured as 192.168.100.2 and the bridge is connected to this
 interface.  The bridge is configured with an IP address of 192.168.100.225
 but as I understand it, this is only the address to use when connecting to
 the web based configuration utility. I have a Linksys access point with IP
 of 192.168.100.1.
 
 Anyway, after attempting connections to these three addresses, my arp table
 looks like this:
 
 ? (192.168.100.1) at (incomplete) on rl0 [ethernet]
 ? (192.168.100.2) at 00:05:5d:d0:ba:67 on rl0 permanent [ethernet]
 ? (192.168.100.225) at (incomplete) on rl0 [ethernet]
 
 I can not get any response from any device beyond the rl0 interface.  I
 setup ipfw to log all traffic to that interface and can see the traffic
 going out:
 
 Sep 27 15:18:04 blacksheep /kernel: ipfw: 50 Accept ICMP:8.0 192.168.100.2
 192.168.100.1 out via rl0
 
 Sep 27 15:24:00 blacksheep /kernel: ipfw: 50 Accept ICMP:8.0 192.168.100.2
 192.168.100.225 out via rl0
 
 Can anyone educate me on arp and if it's my problem, tell me what I might
 need to add to my arp table to get things going?
 
 Thanks,
 
 Drew

I had this problem recently.  Turns out that ipfw when used in
conjunction with bridging (net.link.ether.bridge_ipfw=1) that your
default rule must be to allow all.  You can mitigate this by making your
last rule something like:

deny { tcp or udp } from any to any

This should basically block pretty much any traffic that you are
probably worried about.  To test that this is the problem, disable the
firewall temporarily, maybe with something like:

# sysctl net.link.ether.bridge_ipfw=0

then try your network.  if it works, the re-enable ipfw by setting the
above parameter back to 1.  then take a look at your arp cache expiry
with `arp -an' and make note as to wether the net breaks again as soon
as the arp entry expires.

you can set ipfw to use a default rule of accepting by adding this
option to you kernel config:

options IPFIREWALL_DEFAULT_TO_ACCEPT

Nathan
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