Category Archive Routing and Switching

understanding tacacs-server directed-request command

I find people getting confused on understanding command “tacacs-server directed-request” on Cisco IOS routers. Lets have a look how does it behaves. Suppose we have two tacacs servers configured on a router. tacacs-server host 10.0.0.1 tacacs-…

bootflash and sup-bootflash in Cisco 6509 switch

In my production environment I went through a case where I noticed a behavior of Cisco 6509 switch in which there were bootflash and sup-bootflash where IOS images can be stored and then set the boot variable on either of these. In this switch there was a…

Internet routers hitting 512K limit, some become unreliable

Internet routers hitting 512K limit, some become unreliable At the heart of the issue, the growth of routable networks on the Internet overwhelmed the amount of memory set aside in infrastructure hardware, typically routers and switches, that determines t…

ETHCNTR-3-LOOP_BACK_DETECTED: Loop-back detected on gig0/2

Error : ETHCNTR-3-LOOP_BACK_DETECTED: Loop-back detected on gig0/2 Error code CSCea46385 Symptom: An interface on a Catalyst switch is errordisabled after detecting a loopback. Mar 7 03:20:40: %ETHCNTR-3-LOOP_BACK_DETECTED: Loop-back detected on GigabitEt…

eigrp was continuously flapping between 300 MB ckt

Issue :Eigrp was continuously flapping between 300 MB ckt Jan 31 07:38:06.191 UTC: %DUAL-5-NBRCHANGE: EIGRP-IPv4 224: Neighbor 143.98.217.2 (GigabitEthernet0/0/2) is up: new adjacency Jan 31 07:38:53.433 UTC: %DUAL-5-NBRCHANGE: EIGRP-IPv4 224: Neighbor 14…

Switch Memory issue due to Netflow

Netflow is the mechanism through which we can capture the real time data of the network to analyse the traffic pattern , Bandwidth usage and to troubleshoot the utilization of the network . Some time Netflow cause the Memory utilization causing switch to …

eth_bypass WAE 10.5.76.18 Major The interface InlinePort 1/1/wan is in bypass mode.

Mechanical bypass mode prevents the WAE from becoming a single point of failure and allows traffic to continue to flow between the router and the client while it passes through an unresponsive WAE without being processed.   Should Check on WAE that M…

Understanding OSPF LSA Type-4

Every one who are at this position of preparing for CCIE lab must know about all ospf LSA Types. However LSA Type-4 always remains mysterious and confusing for many of us. So let’s discuss on this LSA Type. Consider a small ospf domain for better un…