Shorewall
2 NIC machine
In /usr/share/doc/shorewall/examples/two-interfaces make the following edits to the following files and then copy them to /etc/shorewall
policy
You may want to allow everything from the local network to the machine and everything from the machine to the net, as well as everything from the machine to the local network in that case add the following to the policy file:
loc fw ACCEPT fw net ACCEPT fw loc ACCEPT
If it's a router it would look something like:
loc net ACCEPT net all DROP info fw all ACCEPT loc all ACCEPT # THE FOLLOWING POLICY MUST BE LAST all all REJECT info
rules
Allready includes the following
?SECTION NEW # Don't allow connection pickup from the net # Invalid(DROP) net all # # Accept DNS connections from the firewall to the network # DNS(ACCEPT) $FW net # # Accept SSH connections from the local network for administration # SSH(ACCEPT) loc $FW SNMP(ACCEPT) loc $FW # # Allow Ping from the local network # Ping(ACCEPT) loc $FW # # Drop Ping from the "bad" net zone.. and prevent your log from being flooded.. # Ping(DROP) net $FW ACCEPT $FW loc icmp ACCEPT $FW net icmp #
So the following needs to be added: NOTE: snmp should only be udp 161, so not sure if tcp is necessary
SNMP(ACCEPT) loc $FW # Public services ACCEPT net fw tcp smtp ACCEPT net fw tcp pop3 # 143 is for IMAP ACCEPT net fw tcp 143 ACCEPT net fw tcp ssh FTP/ACCEPT net fw ACCEPT net fw tcp domain ACCEPT net fw udp domain ACCEPT net fw tcp http ACCEPT net fw tcp https ACCEPT net fw tcp snmp ACCEPT net fw udp snmp
Also, apt uses port 80, so you want to allow outgoing traffic for that:
ACCEPT $FW net tcp http
If you don't do this then you will see ipv6 adresses appear in apt-get
Other services you may want to enable from the machine outwards:
# Things we allow from this machine outward ACCEPT $FW net tcp https SSH(ACCEPT) $FW loc ACCEPT $FW net tcp smtp
For X11 forwarding you will need:
# X11 forwarding ACCEPT fw loc tcp x11 ACCEPT fw loc udp x11
You may want other machines on the local network to access more services:
# Things we accept over the local network FTP/ACCEPT loc $FW ACCEPT loc $FW tcp http
interfaces
If you have multiple ip addresses bound to a single NIC, in order to allow traffic to flow up and down that NIC, you have to add the option
routeback
behind the nic.
the rest
just copy the following files to /etc/shorewall/:
masq routestopped zones
/etc/default/shorewall
startup=1
To get NFS working
On nfs-kernel-server machine: Edit your /etc/shorewall/rules file like this:
# Permit NFS ACCEPT net $FW tcp 111 ACCEPT net $FW udp 111 ACCEPT net $FW udp 2049 ACCEPT net $FW tcp 2049 ACCEPT net $FW tcp 32765:32767 ACCEPT net $FW udp 32765:32767
On nfs-common machine:
# Permit NFS ACCEPT $FW loc tcp 111 ACCEPT $FW loc udp 111 ACCEPT $FW loc udp 2049 ACCEPT $FW loc tcp 2049 ACCEPT $FW loc tcp 32765:32767 ACCEPT $FW loc udp 32765:32767
/etc/default/nfs-common:
STATDOPTS="-p 32765 -o 32766"
/etc/default/nfs-kernel-server:
RPCMOUNTDOPTS="-p 32767"
Make sure in your /etc/services you have the following
nfs 2049/tcp # Network File System nfs 2049/udp # Network File System
old system
The change to /etc/services isn't necessary at all. It just helps produces a nice (sensible) output from netstat -tl on the NFS server.
# /etc/services # NFS ports as per the NFS-HOWTO # http://www.tldp.org/HOWTO/NFS-HOWTO/security.html#FIREWALLS # Listing here does not mean they will bind to these ports. rpc.nfsd 2049/tcp # RPC nfsd rpc.nfsd 2049/udp # RPC nfsd rpc.statd-bc 32765/tcp # RPC statd broadcast rpc.statd-bc 32765/udp # RPC statd broadcast rpc.statd 32766/tcp # RPC statd listen rpc.statd 32766/udp # RPC statd listen rpc.mountd 32767/tcp # RPC mountd rpc.mountd 32767/udp # RPC mountd rcp.lockd 32768/tcp # RPC lockd/nlockmgr rcp.lockd 32768/udp # RPC lockd/nlockmgr rpc.quotad 32769/tcp # RPC quotad rpc.quotad 32769/udp # RPC quotad
/etc/default/quota
RPCRQUOTADOPTS="-p 32769"
You can check which ports are being used with
rpcinfo -p
Shorewall6
http://www.shorewall.net/IPv6Support.html
Shorewall6 is the ipv6 version of shorewall. To get it working you need to do above steps and also:
in /etc/shorewall/shorewall.conf
DISABLE_IPV6=No TC_ENABLED=Internal
/etc/shorewall6/shorewall.conf
TC_ENABLED=No
test using
ip6tables -L
Single NIC Machine
NOTE: snmp should only be udp 161, so not sure if tcp is necessary
/etc/default/shorewall Set startup=1 In /usr/share/doc/shorewall-common/default-config make the following edits to the following files and then copy them to /etc/shorewall interfaces net eth1 82.94.91.79 modules (no edits) policy fw net ACCEPT net all DROP info all all REJECT info NB to drop logging, get rid of the 'info' and replace it with 'crit' or 'err' or get rid of it entirely rules (under SECTION NEW) ACCEPT net fw tcp smtp ACCEPT net fw tcp pop3 ACCEPT net fw tcp ssh FTP/ACCEPT net fw ACCEPT net fw tcp domain ACCEPT net fw udp domain ACCEPT fw net udp domain ACCEPT net fw tcp http ACCEPT fw net tcp http ACCEPT net fw tcp https ACCEPT net fw tcp snmp ACCEPT fw net tcp snmp ACCEPT net fw udp snmp ACCEPT fw net udp snmp ACCEPT net fw tcp 143 ACCEPT net fw udp 143 start dmesg -n5 zones net ipv4 (above fw firewall)
testing
shorewall check