Displaying And Maintaining Gre; Gre Over Ipv4 Tunnel Configuration Example - 3Com MSR 50 Series Configuration Manual

1596 C 81: GRE C
HAPTER
Displaying and
Maintaining GRE
GRE over IPv4 Tunnel
Configuration
Example
ONFIGURATION
If a device needs to reference a link aggregation group for the tunnel interface
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to receive and send packets, the link aggregation group must already exist.
Otherwise, the tunnel interface cannot work properly and the tunnel cannot
communicate. For devices that do not support link aggregation, no link
aggregation group ID needs to be configured on the tunnel interface.
You can enable or disable the checksum function at both ends of the tunnel as
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needed. If the checksum function is enabled at the local end but not at the
remote end, the local end calculates the checksum of a packet to be sent but
does not check the checksum of a received packet. Contrarily, if the checksum
function is enabled at the remote end but not at the local end, the local end
checks the checksum of a received packet but does not calculate the checksum
of a packet to be sent.
When you configure a route through the tunnel, you can configure a static
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route, whose destination address is the destination address of the packet not
encapsulated in GRE and next hop is the address of the tunnel interface at the
remote end. Or, you can enable the dynamic routing protocol on both the
tunnel interface and the router interface connecting the private network so
that the dynamic routing protocol can establish a routing entry that allows the
tunnel to forward packets through the tunnel. It is not allowed to set up a
static route whose destination address is in the subnet of the tunnel interface.
To do...
Display information about a specified or
all tunnel interfaces
Display IPv6 information about a tunnel
interface
Network requirements
Router A and Router B are interconnected through the Internet. Two private IPv4
subnets Group 1 and Group 2 are interconnected through a GRE tunnel between
the two routers.
Network diagram
Figure 444 Network diagram for a GRE over IPv4 tunnel (on routers)
Eth1/0
10.1.1.1/24
IPv4
Group 1
Configuration procedure
1 Configure Router A
# Configure an IPv4 address for interface Ethernet 1/0.
<RouterA> system-view
[RouterA] interface ethernet 1/0
Use the command...
display interface tunnel
[ number ]
display ipv6 interface
tunnel number
S2/0
1.1.1.1/24
IPv 4 network
GRE tunnel
Router A
Tunnel0
10.1.2.1/24
Remarks
Available in any view
Available in any view
S2/1 Eth1/0
10.1.3.1/24
2 .2.2.2/24
Router B
Tunnel 0
10 .1.2.2/24
IPv4
Group 2