Cisco

Cisco Routing – Administrative Distance

Cisco routers are capable of different routing protocols and static and connected routes. Every routing protocol engine has its own distance/metric/weight to decide which route is best. When a routing protocol has chosen its best route, the route is entered into the routing table. The routing engine uses an “administrative distance” per routing protocol to […]

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Cisco IP Phone and NTP

Problem: A Cisco IP phone (in my case 7970G) does not sync with an NTP server. The phone sends an NTP request, receives an NTP response, but does not set its date and time. Solution: It’s a known bug of Cisco’s IP phone software releases 8.3(3) or higher according to Cisco bug id: CSCso40588. Cisco

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Windows Network Load Balancing NLB and Cisco Routers/Switches

Problem: Windows NLB IPs are are not reachable through and from Cisco routers and switches. NLB services could be IIS arrays, Exchange CAS arrays, etc. Solution: NLB mode was set to Multicast. In this mode Windows incorrectly uses multicast mac addresses. Set the NLB mode to Unicast and configure static mac address table entries on

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Cisco has weird naming conventions for groups of interfaces

If you want to bind some ethernet interfaces into one logical interface between two ciscos switches you have to configure an interface first: interface Port-channel 1 then add some interfaces into this new interface: interface GigabitEthernet 1/0/1         channel-group 1 mode active and you can check the status with: show etherchannel 1 summary Three names

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