Allen-Bradley armorstratix 5700, User Manual, Page: 203 / 458

Rockwell Automation Publication 1783-UM007I-EN-P - December 2017 203
Configure Switch Features Chapter 3
Open Shortest Path First
(OSPF) Routing Protocol OSPF is available on the following switches:
•
Stratix 5400 with Layer 3 firmware
•
Stratix 5410 with Layer 3 firmware
•
Stratix 8300 base units
OSPF is an interior gateway routing protocol that uses link states rather than
distance vectors for path selection. OSPF propagates link-state advertisements
(LSAs) rather than routing table updates. Because only LSAs are exchanged
instead of the entire routing tables, OSPF networks converge more quickly
than Routing Information Protocol (RIP) networks.
OSPF uses a link-state algorithm to build and calculate the shortest path to all
known destinations. Each router in an OSPF area contains an identical link-
state database, which is a list of each of the router usable interfaces and
reachable neighbors. Routing decisions are based on cost, which is an
indication of the overhead that is required to send packets across a certain
interface. The router calculates the cost of an interface that is based on link
bandwidth rather than the number of hops to the destination. The cost can be
configured to specify preferred paths.
NTP Association Settings
Status Displays a symbol to indicate the status of the NTP peer association.
* sys.peer
# selected
+ candidate
- outlyer
Configured Displays the status of the NTP peer association.
IP Address Displays the specified IP address for the association:
• For a peer association, the IP address identifies the peer providing, or being
provided, the clock synchronization.
• For a server association, the IP address identifies the time server providing the clock
synchronization.
Prefer If checked, the peer or server is the preferred one that provides synchronization.
Ref Clock Displays a 32-bit code or Internet address that identifies the reference clock of the peer.
Stratum Displays the stratum of the peer.
When Displays the time in seconds since the last NTP packet was received from the peer.
Poll Displays the polling interval in seconds.
Delay Displays the round-trip delay to the peer in milliseconds.
Offset Displays the relative time of the peer clock to the local clock in milliseconds.
Table 76 - NTP Fields (Continued)
Field Description