Guidelines For Configuring Multipoint Receive-Only Tunnels; Multipoint Receive-Only Type And Ip Unnumbered Interfaces For Tunnels - Dell Force10 Z9000 Configuration Manual

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Guidelines for Configuring Multipoint Receive-Only Tunnels

• Maximum number of allowed remote end-points that can be configured for a single multipoint receive-only tunnel is eight.
Maximum number of allowed remote end-points that can be configured for all multipoint receive-only tunnels depends on the
hardware table size to setup termination (it is 512 entries in S4810 and S4820T platforms) and the count is tracked across all of
the tunnel remote end-points configured in the system.
• With multipoint receive-only tunnels, hardware should be handling multiple nested encapsulated packets and this need to work
with the IP MTU set on the physical interface.
• Control plane packets received on the multipoint-receive-only tunnel, are packets destined to the local ip address and routed to
the CPU after decapsulation, would follow the regular processing in the TCP/IP stack. A response to these packets is only
possible if the route back to the sender does not fall on a receive-only tunnel.
• Multipath over more than one VLAN interfaces will not be working for packets routed over the tunnel interface. This is inherited
from the current implementation and this is not applicable for the receive-only tunnels functionality discussed above.
• IP tunnel interfaces are supported over ECMP paths to the next hop. ECMP paths over IP tunnel interfaces are supported. ARP
and neighbor resolution for the IP tunnel next hop are supported.
Multipoint Receive-Only Type and IP Unnumbered Interfaces for
Tunnels
This is a new type of tunnel that is expected to only decapsulate packets from remote end points but never forwards packets on the
tunnel. Additional level of protection on the receive-only type IP tunnels is available by allowing only a given prefix/range of remote
peers. IP unnumbered interface address configuration on the IP Tunnels is now supported.
Tunnel interface's operational status will always remain UP once tunnel is configured to work in multipoint-receive-only mode.
Allowed remote addresses configured for multipoint-receive-only type tunnel are setup only for decapsulation and hence they are not
marked for neighbor resolution like the regular tunnel's destination address. Connected route for the tunnel interface's IP subnet will
not be pointing towards the tunnel and it will be pointing towards CPU for the receive-only tunnels. Tunnel interface can function as
IP unnumbered interface with no IP address assigned on it
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Tunneling