23
Examples
# Enable sending ICMP time exceeded messages.
<Sysname> system-view
[Sysname] ip ttl-expires enable
ip unreachables enable
Use
ip unreachables enable
to enable sending ICMP destination unreachable messages.
Use
undo ip unreachables enable
to disable sending ICMP destination unreachable
messages.
Syntax
ip unreachables enable
undo ip unreachables enable
Default
Sending ICMP destination unreachable messages is disabled.
Views
System view
Predefined user roles
network-admin
Usage guidelines
A device sends ICMP destination unreachable messages by following these rules:
•
The device sends the source an ICMP network unreachable message when the following
conditions are met:
The received packet does not match any route.
No default route exists in the routing table.
•
The device sends the source an ICMP protocol unreachable message when the following
conditions are met:
The received packet is destined for the device.
The transport layer protocol of the packet is not supported by the device.
•
The device sends the source an ICMP port unreachable message when the following
conditions are met:
The received UDP packet is destined for the device.
The packet's port number does not match the running process.
•
The device sends the source an ICMP source route failed message when the following
conditions are met:
The source uses Strict Source Routing to send packets.
The intermediate device finds that the next hop specified by the source is not directly
connected.
•
The device sends the source an ICMP fragmentation needed and DF set message when the
following conditions are met:
The MTU of the sending interface is smaller than the packet.
The packet has Don't Fragment set.
Examples
# Enable
sending ICMP destination unreachable messages.
Summary of Contents for SOHO IE4300
Page 285: ...i Contents Tcl commands 1 cli 1 tclquit 1 tclsh 2...
Page 288: ...i Contents Python commands 1 exit 1 python 1 python filename 2...
Page 291: ...i Contents Automatic configuration commands 1 autodeploy udisk enable 1...
Page 323: ...25 Sysname Ten GigabitEthernet1 0 51 undo shutdown Related commands irf port...
Page 465: ...ii stp vlan enable 55 vlan mapping modulo 55...
Page 602: ...12 Related commands display mvrp statistics...
Page 609: ...i Contents VLAN mapping commands 1 display vlan mapping 1 vlan mapping 2...
Page 678: ...9 Related commands reset pppoe relay statistics...
Page 846: ...i Contents Basic IP forwarding commands 1 display fib 1 ip forwarding table save 2...
Page 1770: ...i Contents Time range commands 1 display time range 1 time range 1...
Page 2026: ...34 Related commands display mac authentication...
Page 2028: ...ii...
Page 2143: ...i Contents User profile commands 1 display user profile 1 user profile 2...
Page 2308: ...61 ipsec transform set...
Page 2531: ...i Contents SAVI commands 1 ipv6 savi down delay 1 ipv6 savi log enable 1 ipv6 savi strict 2...
Page 2534: ...3 Sysname ipv6 savi strict Related commands ipv6 verify source...
Page 2791: ...14 Sysname track 1 Related commands delay display track...
Page 2939: ...9 sntp authentication keyid sntp reliable authentication keyid...
Page 2967: ...27 Related commands apply poe profile poe enable poe max power interface view poe priority...