TOPEX Bytton (HSPA+ / LTE)
ByttonLTE(full)_genericUsermanual_sw306FAS_revN.1.docx
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Netmask
- Netmask for IP tunnel.
Key
- a “Key” for the GRE tunnel. It is a 32 bit number (values from 0 to 4294967295).
This Key field is intended to be used for identifying an individual traffic flow within a tunnel.
Note that this Key field
is not involved in any sort of sec
urity (despite its name.)
Examples
:
When you will set:
Int. Remote Endpoint Local Endpoint IP tunnel Netmask Key
gret1 172.168.1.10 0.0.0.0 10.10.10.2 255.255.255.252 off
This will create a GRE tunnel with interface "gret1" from any local interface IP with remote 172.168.1.10.
The local gret1 interface will have IP: 10.10.10.2 and net mask 255.255.255.252
Also, this will automatically add a route towards this interface, that you will be able to see in see
it in Routing > Routes, in this example you will have:
Destination Gateway Genmask Flags Metric Ref Use Iface
10.10.10.0 0.0.0.0 255.255.255.252 U 0 0 0 gret1
Depending upon the actual requirements of your application, you may use a single GRE tunnel, or
several, with different parameters for each tunnel gret1, gret2, gret3 and so on.
See the first two gre tunnels now present in the routing table of Bytton LTE:
Kernel IP routing table
Destination Gateway Genmask Flags Metric Ref Use Iface
192.168.144.208 0.0.0.0 255.255.255.254 U 0 0 0 gret2
10.10.10.0 0.0.0.0 255.255.255.252 U 0 0 0 gret1
In the “Interfaces” drop list, together with the physical interfaces and the other
logical interfaces of the equipment:
And also in the firewall rules:
Firewall view rule
# Generated by iptables-save v1.4.10 on Tue Dec 11 15:21:00 2012
:OUTPUT ACCEPT [175:31270]
-A INPUT -i lo -j ACCEPT
-A INPUT -p gre -j ACCEPT
-A INPUT -m state --state RELATED,ESTABLISHED -j ACCEPT
-A INPUT -i ppp3 -j ACCEPT
-A FORWARD -i br0 -j ACCEPT
-A FORWARD -p gre -j ACCEPT
-A FORWARD -m state --state RELATED,ESTABLISHED -j ACCEPT
COMMIT
# Completed on Tue Dec 11 15:21:00 2012
