Re: [squid-users] Linux as router (Gateway Server)

From: Ow Mun Heng <[email protected]>
Date: Wed, 16 Feb 2005 15:36:49 +0800

On Wed, 2005-02-16 at 00:03, Navneet Choudhary wrote:
> hi list,
>
> i require help yours side.
>
> Squid Server is serving as Proxy server, Gateway & Firewall
>
> Problem:
> Squid daemon dies at startup.
>
> Feb 12 09:15:33 squid (squid): Cannot open HTTP Port
>
> Why my iptables rule blocking squid to open HTTP port.
>

Is it possible for you to remove the iptables rules on this system to
try out?

If not, perhaps you can try a ethereal dump to determine what Squid is
trying to open and gets denied.

what about yout firewall logs?

> Note: existing rule being attached at the end of mail
>
> Since, process will not die if I disable/flush my rules?
>
> Squid being started from /etc/rc.local
>
> Where i am doing mistakes?
>
> Please suggest since its causing startup hiccup
>
> Thanks & regards,
>
> Navneet Choudhary
>
> Updates & quick recap
>
> 1.> Basically I want clients to be able to :
>
> a). Send and receives mails from mail.ISP.net [X.X.X.X] and
> sometimes from X.X.X.X
> Status: Working
> b). Browse the net through squid [3128]
> Status: Working
>
> c). Use Jabber [??], MSN [1863] and Yahoo [5050]
> Status: Working
>
> d) Down and upload data using ftp from X.X.X.K & X.X.X.Z
>
> Status: Working
> e) Down and upload data using SONICMQ [IP & Port?]
>
> Status: Require HELP
> e) Allow SSH connection to this system [eth0].
> Status: Working
> f) We can ping/trace route by domain name i.e. ping yahoo.com
> Status: Working
>
> 2.What i am using?
>
> My network configuration is as follows: -
>
> WAN
> |
> eth1
> (172.21.0.133/28)
> |
> |
> Red Hat 9
> [Squid Proxy, Gateway ,firewall & FTP]
> |
> |
> |
> (192.168.0.0/16)
> eth0
> |
> ---- SWITCH----------
> |
> |
> |
> LAN
>
> where:-
> eth0-Intel Corp. 82557/8/9 [Ethernet Pro 100]
> eth1-Broadcom Corporation NetXtreme BCM5702 Gigabit Ethernet
>
> Kernel 2.4.20-8
>
> iptables v1.2.7a
>
> 3.What I have done:-
>
> a)Enabled IP forwarding by adding
> vi /etc/sysctl.conf
>
> # Controls IP packet forwarding
> net.ipv4.ip_forward = 1
>
> b)Automatic loading of modules by adding
> vi /etc/rc.local
>
> /sbin/insmod ip_nat_ftp
> /sbin/insmod ip_conntrack_ftp
>
> b)Firewall rules as follows:-
> # Generated by iptables-save v1.2.7a on Thu Feb 10 20:02:43 2005
> *mangle
> :PREROUTING ACCEPT [1308:428675]
> :INPUT ACCEPT [1308:428675]
> :FORWARD ACCEPT [0:0]
> :OUTPUT ACCEPT [1273:553710]
> :POSTROUTING ACCEPT [1273:553710]
> -A PREROUTING -p tcp -m tcp --tcp-flags FIN,SYN,RST,PSH,ACK,URG
> FIN,PSH,URG -j DROP
> -A PREROUTING -p tcp -m tcp --tcp-flags FIN,SYN,RST,PSH,ACK,URG NONE -j DROP
> -A PREROUTING -p tcp -m tcp --tcp-flags SYN,RST SYN,RST -j DROP
> -A PREROUTING -p tcp -m tcp --tcp-flags FIN,SYN FIN,SYN -j DROP
> -A PREROUTING -p tcp -m tcp --tcp-flags FIN,SYN,RST,PSH,ACK,URG
> FIN,PSH,URG -j DROP
> -A PREROUTING -p tcp -m tcp --tcp-flags FIN,SYN,RST,PSH,ACK,URG NONE -j DROP
> -A PREROUTING -p tcp -m tcp --tcp-flags SYN,RST SYN,RST -j DROP
> -A PREROUTING -p tcp -m tcp --tcp-flags FIN,SYN FIN,SYN -j DROP
> -A PREROUTING -p tcp -m tcp --tcp-flags FIN,SYN,RST,PSH,ACK,URG
> FIN,PSH,URG -j DROP
> -A PREROUTING -p tcp -m tcp --tcp-flags FIN,SYN,RST,PSH,ACK,URG NONE -j DROP
> -A PREROUTING -p tcp -m tcp --tcp-flags SYN,RST SYN,RST -j DROP
> -A PREROUTING -p tcp -m tcp --tcp-flags FIN,SYN FIN,SYN -j DROP
> -A PREROUTING -p tcp -m tcp --tcp-flags FIN,SYN,RST,PSH,ACK,URG
> FIN,PSH,URG -j DROP
> -A PREROUTING -p tcp -m tcp --tcp-flags FIN,SYN,RST,PSH,ACK,URG NONE -j DROP
> -A PREROUTING -p tcp -m tcp --tcp-flags SYN,RST SYN,RST -j DROP
> -A PREROUTING -p tcp -m tcp --tcp-flags FIN,SYN FIN,SYN -j DROP
> COMMIT
> # Completed on Thu Feb 10 20:02:43 2005
> # Generated by iptables-save v1.2.7a on Thu Feb 10 20:02:43 2005
> *nat
> :PREROUTING ACCEPT [10233:846887]
> :POSTROUTING ACCEPT [71:4821]
> :OUTPUT ACCEPT [67:4688]
> -A POSTROUTING -s 192.168.0.0/255.255.0.0 -o eth1 -j SNAT --to-source
> 172.21.0.132
> COMMIT
> # Completed on Thu Feb 10 20:02:43 2005
> # Generated by iptables-save v1.2.7a on Thu Feb 10 20:02:43 2005
> *filter
> :INPUT DROP [0:0]
> :FORWARD DROP [0:0]
> :OUTPUT DROP [0:0]
> -A INPUT -s 127.0.0.1 -j ACCEPT
> -A INPUT -m state --state RELATED,ESTABLISHED -j ACCEPT
> -A INPUT -i eth0 -p tcp -m tcp --sport 1024:65535 --dport 3128
> --tcp-flags SYN,RST,ACK SYN -j ACCEPT
> -A INPUT -i eth0 -p tcp -m tcp --sport 1024:65535 --dport 22
> --tcp-flags SYN,RST,ACK SYN -j ACCEPT
> -A INPUT -i eth0 -p tcp -m tcp --sport 1024:65535 --dport 21
> --tcp-flags SYN,RST,ACK SYN -j ACCEPT
> -A INPUT -i eth0 -p tcp -m tcp --sport 1024:65535 --dport 20
> --tcp-flags SYN,RST,ACK SYN -j ACCEPT
> -A INPUT -p udp -j DROP
> -A INPUT -p tcp -m tcp --tcp-flags SYN,RST,ACK SYN -j DROP
> -A INPUT -p icmp -m icmp --icmp-type 8 -j ACCEPT
> -A FORWARD -m state --state RELATED,ESTABLISHED -j ACCEPT
> -A FORWARD -i eth0 -o eth1 -p udp -m udp --sport 1024:65535 --dport 53 -j ACCEPT
> -A FORWARD -i eth0 -o eth1 -p tcp -m tcp --sport 1024:65535 --dport 25
> --tcp-flags SYN,RST,ACK SYN -j ACCEPT
> -A FORWARD -i eth0 -o eth1 -p tcp -m tcp --sport 1024:65535 --dport
> 110 --tcp-flags SYN,RST,ACK SYN -j ACCEPT
> -A FORWARD -i eth0 -o eth1 -p tcp -m tcp --sport 1024:65535 --dport 21 -j ACCEPT
> -A FORWARD -i eth0 -o eth1 -p tcp -m tcp --sport 1024:65535 --dport 20 -j ACCEPT
> -A FORWARD -i eth0 -o eth1 -p tcp -m tcp --sport 1024:65535 --dport
> 1863 --tcp-flags SYN,RST,ACK SYN -j ACCEPT
> -A FORWARD -i eth0 -o eth1 -p tcp -m tcp --sport 1024:65535 --dport
> 5050 --tcp-flags SYN,RST,ACK SYN -j ACCEPT
> -A FORWARD -p icmp -m icmp --icmp-type 8 -j ACCEPT
> -A OUTPUT -m state --state RELATED,ESTABLISHED -j ACCEPT
> -A OUTPUT -p udp -m udp --sport 1024:65535 --dport 53 -j ACCEPT
> -A OUTPUT -o eth1 -p tcp -m tcp --sport 1024:65535 --dport 80
> --tcp-flags SYN,RST,ACK SYN -m owner --uid-owner squid -j ACCEPT
> -A OUTPUT -o eth1 -p tcp -m tcp --sport 1024:65535 --dport 443
> --tcp-flags SYN,RST,ACK SYN -m owner --uid-owner squid -j ACCEPT
> -A OUTPUT -p icmp -m icmp --icmp-type 8 -j ACCEPT
> COMMIT
> # Completed on Thu Feb 10 20:02:43 2005

--
Ow Mun Heng
Gentoo/Linux on DELL D600 1.4Ghz 
98% Microsoft(tm) Free!! 
Neuromancer 15:35:37 up 6:26, 5 users, 
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Received on Wed Feb 16 2005 - 00:39:05 MST

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