Service Manual

Direct, Lo 0
--More--
Dell Networking OS installs a next hop that is on the directly connected subnet of current IP address on
the interface (for example, if interface TenGigabitEthernet 1/1 is on 172.31.5.0 subnet, Dell
Networking OS installs the static route).
Dell Networking OS also installs a next hop that is not on the directly connected subnet but which
recursively resolves to a next hop on the interface's configured subnet. For example, if te 1/1 has ip
address on subnet 2.2.2.0 and if 172.31.5.43 recursively resolves to 2.2.2.0, Dell Networking OS installs the
static route.
• When the interface goes down, Dell Networking OS withdraws the route.
• When the interface comes up, Dell Networking OS re-installs the route.
• When the recursive resolution is “broken,” Dell Networking OS withdraws the route.
• When the recursive resolution is satisfied, Dell Networking OS re-installs the route.
Configure Static Routes for the Management Interface
When an IP address that a protocol uses and a static management route exists for the same prefix, the
protocol route takes precedence over the static management route.
To configure a static route for the management port, use the following command.
• Assign a static route to point to the management interface or forwarding router.
CONFIGURATION mode
management route ip-address mask {forwarding-router-address |
ManagementEthernet slot/port}
Example of the show ip route static Command
To view the configured static routes for the management port, use the show ip management-route
command in EXEC privilege mode.
Dell#show ip management-route
Destination Gateway State Route Source
----------- ------- ----- ------------
10.16.0.0/16 ManagementEthernet 1/1 Connected Connected
172.16.1.0/24 10.16.151.4 Active Static
IPv4 Path MTU Discovery Overview
This functionality is supported on the platform.
The size of the packet that can be sent across each hop in the network path without being fragmented is
called the path maximum transmission unit (PMTU). This value might vary for the same route between
two devices, mainly over a public network, depending on the network load and speed, and it is not a
consistent value. The MTU size can also be different for various types of traffic sent from one host to the
same endpoint.
Path MTU discovery (PMTD) identifies the path MTU value between the sender and the receiver, and uses
the determined value to transmit packets across the network. PMTD, as described in RFC 1191, denotes
that the default byte size of an IP packet is 576. This packet size is called the maximum transmission unit
(MTU) for IPv4 frames. PMTD operates by containing the do not fragment (DF) bit set in the IP headers of
464
IPv4 Routing