Re: [LARTC] masquerade and mac problem
Hi,
I recommend you to use the following script:
#!/bin/sh
# Deleting all existing rules in all chains
# and theleting user created chains
iptables -t nat -F
iptables -t filter -F
iptables -t mangle -F
iptables -t nat -X
iptables -t filter -X
iptables -t mangle -X
# Setting the default policy to DROP, so those packets which are not
# ACCEPT-ed are dropped at the end
iptables -P FORWARD DROP
# Masquerading
iptables -t nat -A POSTROUTING -o eth0 -j MASQUERADE
# Allowing outgoing packets from specific users with correct mac
# addresses.
# Add same line for each client with proper ip and mac addresses
iptables -A FORWARD -s 192.168.10.2 -m mac --mac-source\
00:11:22:33:44:55 -j ACCEPT
# Allowing all incomming packets which belongs to a clients
# connection
iptables -A FORWARD -m state --state ESTABLISHED,RELATED -j ACCEPT
---
You should consider the INPUT and OUTPUT chains on your router, and to
set them proper rules regarding your needs.
Also you'll need connection tracking support from the kernel.
The 'ip_conntrack' and similar modules will be useful if you don't have
connection tracking support compilled into the kernel itself.
I hope this will help!!!
Regards: Ilia Lindov
Sorin Capra wrote:
Hello guys
I don't know if this thing has been posted before (if it was , please
forgive me).
I have 7 computers at home and I want all of them to have access to the
internet. In order to do that , I set up a linux router (2 network
cards) as a usual router (eth0 : 82.77.69.75 - internet connection ;
eth1 : 192.168.10.1 - local network) . The other computers have ips
ranging from 192.168.10.2 to 192.168.10.8 . The linux router masquerades
the other computers. The problem I have is that I want to do the
masquerading based on mac AND the ip not only on the ip (so if I change
the ip on a computer and use another ip from another computer which is
down , the masquerading process shouldn't work)
What I came up with is this :
-
#!/bin/sh
ipt="/usr/sbin/iptables"
$ipt -F
$ipt -F -t nat
$ipt -t filter -N computer1 >/dev/null 2>&1
$ipt -t filter -N computer2 >/dev/null 2>&1
$ipt -t filter -N computer3 >/dev/null 2>&1
$ipt -t filter -N computer4 >/dev/null 2>&1
$ipt -t filter -N computer5 >/dev/null 2>&1
$ipt -A FORWARD -s 192.168.10.2 -j computer1
$ipt -A FORWARD -s 192.168.10.3 -j computer2
$ipt -A FORWARD -s 192.168.10.4 -j computer3
$ipt -A FORWARD -s 192.168.10.5 -j computer4
$ipt -A FORWARD -s 192.168.10.6 -j computer5
$ipt -A computer1 -m mac --mac-source 00:c0:df:f7:7c:3b -j ACCEPT
$ipt -A computer2 -m mac --mac-source 00:06:4f:0f:3b:c1 -j ACCEPT
$ipt -A computer3 -m mac --mac-source 00:0c:6e:90:39:6a -j ACCEPT
$ipt -A computer4 -m mac --mac-source 00:90:27:5f:5e:78 -j ACCEPT
$ipt -A computer5 -m mac --mac-source 00:90:27:9b:3c:a2 -j ACCEPT
$ipt -A POSTROUTING -t nat -s 192.168.10.2 -j MASQUERADE
$ipt -A POSTROUTING -t nat -s 192.168.10.3 -j MASQUERADE
$ipt -A POSTROUTING -t nat -s 192.168.10.4 -j MASQUERADE
$ipt -A POSTROUTING -t nat -s 192.168.10.5 -j MASQUERADE
$ipt -A POSTROUTING -t nat -s 192.168.10.6 -j MASQUERADE
#$ipt -P FORWARD DROP
If I uncomment the last line ("#$ipt -P FORWARD DROP") the router
won't forward any packets. What am I doing wrong ?
Thank
you in advance,
Sorin
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Re: [LARTC] masquerade and mac problem
On Sat, 4 Sep 2004 08:21:21 -0700 (PDT), Sorin Capra wrote
>Thank you for the quick reply
>
>It works now , but I still have one question : why didn't it work before
(in FORWARD) ? It should have worked , shouldn't it ?
1) Have you tried to do:
iptables -t filter -L -nv
and check if counters are non-zero for rules with mac source matches?
2) In kernel source I have found something like this
(net/ipv4/netfilter/ipt_mac.c file):
static int
ipt_mac_checkentry(const char *tablename,
const struct ipt_ip *ip,
void *matchinfo,
unsigned int matchsize,
unsigned int hook_mask)
{
/* FORWARD isn't always valid, but it's nice to be able to do --RR */
if (hook_mask
& ~((1 << NF_IP_PRE_ROUTING) | (1 << NF_IP_LOCAL_IN)
| (1 << NF_IP_FORWARD))) {
printk("ipt_mac: only valid for PRE_ROUTING, LOCAL_IN or
FORWARD.\n");
return 0;
}
if (matchsize != IPT_ALIGN(sizeof(struct ipt_mac_info)))
return 0;
return 1;
}
Maybe during traversing filter/FORWARD hook mac field in skb structure is not
valid, because packet is beeing forwarded between two ifaces.
> Bests,
> Sorin
Bests,
Tomasz Chilinski
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Re: [LARTC] masquerade and mac problem
On Sat, 4 Sep 2004 05:19:39 -0700 (PDT), Sorin Capra wrote > $ipt -t filter -N computer1 >/dev/null 2>&1 > $ipt -t filter -N computer2 >/dev/null 2>&1 > $ipt -t filter -N computer3 >/dev/null 2>&1 > $ipt -t filter -N computer4 >/dev/null 2>&1 > $ipt -t filter -N computer5 >/dev/null 2>&1 > > $ipt -A FORWARD -s 192.168.10.2 -j computer1 > $ipt -A FORWARD -s 192.168.10.3 -j computer2 > $ipt -A FORWARD -s 192.168.10.4 -j computer3 > $ipt -A FORWARD -s 192.168.10.5 -j computer4 > $ipt -A FORWARD -s 192.168.10.6 -j computer5 > > $ipt -A computer1 -m mac --mac-source 00:c0:df:f7:7c:3b -j ACCEPT > $ipt -A computer2 -m mac --mac-source 00:06:4f:0f:3b:c1 -j ACCEPT > $ipt -A computer3 -m mac --mac-source 00:0c:6e:90:39:6a -j ACCEPT > $ipt -A computer4 -m mac --mac-source 00:90:27:5f:5e:78 -j ACCEPT > $ipt -A computer5 -m mac --mac-source 00:90:27:9b:3c:a2 -j ACCEPT > > $ipt -A POSTROUTING -t nat -s 192.168.10.2 -j MASQUERADE > $ipt -A POSTROUTING -t nat -s 192.168.10.3 -j MASQUERADE > $ipt -A POSTROUTING -t nat -s 192.168.10.4 -j MASQUERADE > $ipt -A POSTROUTING -t nat -s 192.168.10.5 -j MASQUERADE > $ipt -A POSTROUTING -t nat -s 192.168.10.6 -j MASQUERADE > > #$ipt -P FORWARD DROP > Use mac source match in chain PREROUTING of nat table. Additionalny tests will be working for first packets of connections (less load). >Thank you in advance, >Sorin Bests, Tomasz Chilinski ___ LARTC mailing list / [EMAIL PROTECTED] http://mailman.ds9a.nl/mailman/listinfo/lartc HOWTO: http://lartc.org/
[LARTC] masquerade and mac problem
Hello guys
I don't know if this thing has been posted before (if it was , please forgive me).
I have 7 computers at home and I want all of them to have access to the internet. In order to do that , I set up a linux router (2 network cards) as a usual router (eth0 : 82.77.69.75 - internet connection ; eth1 : 192.168.10.1 - local network) . The other computers have ips ranging from 192.168.10.2 to 192.168.10.8 . The linux router masquerades the other computers. The problem I have is that I want to do the masquerading based on mac AND the ip not only on the ip (so if I change the ip on a computer and use another ip from another computer which is down , the masquerading process shouldn't work)
What I came up with is this :
-
#!/bin/shipt="/usr/sbin/iptables"
$ipt -F$ipt -F -t nat
$ipt -t filter -N computer1 >/dev/null 2>&1$ipt -t filter -N computer2 >/dev/null 2>&1$ipt -t filter -N computer3 >/dev/null 2>&1$ipt -t filter -N computer4 >/dev/null 2>&1$ipt -t filter -N computer5 >/dev/null 2>&1
$ipt -A FORWARD -s 192.168.10.2 -j computer1
$ipt -A FORWARD -s 192.168.10.3 -j computer2
$ipt -A FORWARD -s 192.168.10.4 -j computer3
$ipt -A FORWARD -s 192.168.10.5 -j computer4$ipt -A FORWARD -s 192.168.10.6 -j computer5
$ipt -A computer1 -m mac --mac-source 00:c0:df:f7:7c:3b -j ACCEPT$ipt -A computer2 -m mac --mac-source 00:06:4f:0f:3b:c1 -j ACCEPT$ipt -A computer3 -m mac --mac-source 00:0c:6e:90:39:6a -j ACCEPT$ipt -A computer4 -m mac --mac-source 00:90:27:5f:5e:78 -j ACCEPT$ipt -A computer5 -m mac --mac-source 00:90:27:9b:3c:a2 -j ACCEPT
$ipt -A POSTROUTING -t nat -s 192.168.10.2 -j MASQUERADE$ipt -A POSTROUTING -t nat -s 192.168.10.3 -j MASQUERADE$ipt -A POSTROUTING -t nat -s 192.168.10.4 -j MASQUERADE$ipt -A POSTROUTING -t nat -s 192.168.10.5 -j MASQUERADE$ipt -A POSTROUTING -t nat -s 192.168.10.6 -j MASQUERADE#$ipt -P FORWARD DROP
If I uncomment the last line ("#$ipt -P FORWARD DROP") the router won't forward any packets. What am I doing wrong ?
Thank you in advance,
Sorin
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