| add_docsetworkflow_for_workflowtechpubs |
|---|
| AUTH1 | |
|---|
bscoggins| REV5 | | | DEV1REV6 | |
|---|
ssekhar| REV3 | | LDEV1 | bscoggins |
|---|
| SVT1 | radaikalam |
|---|
LSVT1 | bscoggins | | REV1 | |
|---|
|
...
| Caption |
|---|
| 0 | Table |
|---|
| 1 | SBC Probing Mechanism Types |
|---|
|
| Probing Mechanism | SBC Platforms | Affected Ports | Purpose |
|---|
| Physical link detection | All | All ports on both active and backup CEs | - Detects the presence of the port cable and that the adjacent device is powered on (enabled by default on all physical ports configured by Link Monitor except for any ports administratively disabled or set out-of-service).
- Reports any hardware failures to NRS and Link Verification Manager (LVM) tasks.
| | ICMP ping | All | Active ports only | Checks two-way connectivity between port and the configured destination (adjacent router) by sending ICMP Ping messages at configured intervals to the destination.| Note |
|---|
| When destination IP address is configured in a Link Monitor, ICMP Ping is enabled along with physical link detection. By setting the destination IP address to NULL (0.0.0.0), only physical link detection can be enabled. |
| | ARP ACD/ICMPv6 NUD* | SBC 7000 only | Standby ports only | Performs active checking of Verifies physical media by checking two-way traffic through at least the local Ethernet interface, the cable, and the adjacent layer 2/3 switching function. Checks are Layer 3 verification is accomplished using ARP ACD Probes (for IPv4) or Neighbor Discovery (for IPv6) mechanisms to probe an arbitrary, operator-specified target IP address on a local IP subnet, typically an the address of a the next-hop router (Gateway IP address). Depending on the address family (IPv4/IPv6) of the gateway IP address configured, either ARP ACD or ICMPv6 NUD probing messages are sent in such a way that explicit assignments of IP addresses to the standby ports are not required. See below for specifics on IPv4 ARP ACD requirements. When IP Target is to 0.0.0.0 and/or “probeOnStandby” is disabled, only the physical link state between active/standby Checks the link state between port and the adjacent router is monitored. |
* Address Resolution Protocol - Address Conflict Detection / Internet Control Message Protocol Version 6 – Neighbor Unreachability Detection |
...
- Sender IP address of 0.0.0.0. The use of 0.0.0.0 is compatible with rfc 5227 on IPv4 Address Conflict Detection. This is convenient to use on standby ports since IP addresses are not assigned for standby ports.
- Sender hardware address containing the current local MAC address assigned to the sending port.
- Target IP address containing the configured target IP address to be probed.
- Target hardware address containing all zeros. The ARP request is sent on the LAN using L2 broadcast.
The target can be expected is required to respond to the ARP probe with an ARP Response using L2 unicasthaving an L2 unicast MAC as the DESTINATION and SOURCE. If the target replies with a GARP or ARP request in the form of a broadcast, the
drops these requests due to DDOS functionality enabled in the application code.Refer to Link Detection Group - CLI for command to disable probe functionality on the Standby port if router can not reply to the ARP probe with a unicast destination MAC address.
IPv6 ICMPv6 NUD
If the destination address configured is an IPv6 address, then IPv6 probing would be initiated using Neighbor Unreachability Detection mechanism (RFC 4861 section 7). This is based on Neighbor Solicitation and Neighbor Advertisement ICMPv6 messages.
...