Welcome
First of all, may I welcome you to my site. My name is Chris and I'm from the UK and work as a Systems Engineer for Cisco. This blog was initially created to post up my subnetting technique but has now got more stuff to do with attaining Cisco certifications. Either way I really hope that the content is sufficent for your needs and I look forward to hearing your feedback. If you find that the content really helps you please feel free to donate using the PayPal link on the right.
To view the index of all my articles please click here.
VLAN Trunking - Remembering which combination creates a Trunk Link
Thursday, 6 December 2007
Ah, you've probably seen the table and thought to yourself "that doesn't look bad." Well let's make it easier:
1. If one end of the link is configured as an access port then the link will NOT trunk.
2. If BOTH ends of the link are AUTO then the link will NOT trunk
3. If one end is a trunk and the other is auto BUT THE TRUNK PORT IS CONFIGURED FOR NO-NEGOTIATION then the link will NOT trunk.
4. ALL OTHER COMBINATIONS WILL TRUNK
Posted byChris Bloomfield at 14:37 4 comments
Labels: 802.1q, auto, isl, negotiate, non-broadcast, trunk, trunking, vlan, vtp
OSPF and NBMA Networks
Tuesday, 27 November 2007
Confused about which NBMA network type requires a DR/BDR or neighbours to be statically defined? Worry no longer..............................
If the keyword nonbroadcast is within the network type (i.e. ip ospf network non-broadcast, or ip ospf network point-to-multipoint non-broadcast) then neighbours must be defined.
If the keyword point is within the network type (i.e. ip ospf network point-to-point, ip ospf network point-to-multipoint, ip ospf network point-to-multipoint non-broadcast) then a DR/BDR is NOT elected.
You may see a question which has an output showing the network type as point-to-multipoint. It will then ask you to choose a couple of correct answers. From above we know the answer to be that DR/BDR are not elected and neighbours do not need to be statically defined.
HTH!
Posted byChris Bloomfield at 15:47 2 comments
Labels: bdr, broadcast, dr, frame relay, multipoint, nbma, non-broadcast, ospf, point
