Well, this is a short one but convenient as the title says:)
After the connection between two switches could not be established I went to see the log of the uplink switch and the first thing I have noticed was this: %LINK-3-UPDOWN: Interface FastEthernet0/1, changed state to up %LINEPROTO-5-UPDOWN: Line protocol on Interface FastEthernet0/1, changed state to up %SPANTREE-7-RECV_1Q_NON_TRUNK: Received 802.1Q BPDU on non trunk FastEthernet0/1 VLAN300. […]
After moving your DHCP server and it doesn’t receive client requests but everything is “OK” with the server, then that could cause a problem in your corporate environment:)
MTU size never crossed my mind until MPLS designed network came to the picture. After adding a switch to the network, OSPF got up, but BGP was going up and down and up and down… That led to the MTU mismatch because bigger frames are needed in a MPLS network.
Maybe you came across a problem where you have a Cisco switch worth a few thousand dollars but you just don’t have a Cisco SFP which is also not cheap or it had malfunctioned and you are looking for an alternative. I have recently encountered that kind of situation (the first one) but there is […]