Skip to main content

Best Practices for VLAN Design

Following these General Best practices when implementing VLANs can help to design and implement VLANs in a simple, secure and less troubleshooting-requiring Campus Network.
  • For the Local VLANs model, it is usually recommended to have only one to three VLANs per access module and limit those VLANs to a couple of access switches and the distribution switches.
  • Avoid using VLAN 1 as the “blackhole” for all unused ports. Use any other VLAN except 1 to assign all the unused ports to it.
  • Try to always have separate voice VLANs, data VLANs, management VLANs, native VLANs, blackhole VLANs, and default VLANs (VLAN 1).
  • In the local VLANs model, avoid VTP; it is feasible to use manually allowed VLANs in a network on trunks.
  • For trunk ports, turn off DTP and configure it manually. Use IEEE 802.1Q rather than ISL because it has better support for QoS and is a standard protocol.
  • Manually configure access ports that are not specifically intended for a trunk link.
  • Prevent all data traffic from VLAN 1; only permit control protocols to run on VLAN 1 (DTP, VTP, STP BPDUs, PAgP, LACP, CDP, and such.).
  • Avoid using Telnet because of security risks; enable SSH support on management VLANs.
Labels:

Comments

Post a Comment

Popular posts from this blog

How to import Putty Saved Connections to mRemoteNG

Just started using mRemoteNG and its being very cool to connect to different remote connection with different protocols e.g Window Remote Desktop, VNC to Linux, SSH, HTTP connection etc. from a single application. As new user I configured some remote desktop connection which was quite easy to figure out. But when I wanted to add SSH connections, it came in my mind to import all of the saved connections in the putty. But I couldn't figure it out how can it be done, though it was quite easy and here are the steps. Open your mRemoteNG Create a folder if you want segregation of multiple networks Create a new connection Enter the IP address of remote server under connection in Config pane Under the config pane, select protocol " SSH version 2 ".  Once you select protocol to SSH version 2 you are given option to import putty sessions, as shown in the snap below. In the above snap, I have imported CSR-AWS session from my saved sessions in Putty.
1 comment
Read more

BGP Local Preference Controlling Outbound Traffic in BGP

In BGP, Local Preference is used to control the outbound traffic path. It helps you decide which egress point (exit point) should be used when you have multiple connections to external networks, such as ISPs. Local Preference is an attribute that is local to your AS and is shared with all iBGP peers but not with eBGP neighbors. Higher Local Preference = More preferred outbound path. Example Scenario : You have two external links: ISP1 (via CE1) and ISP2 (via CE2). You want traffic to prefer ISP1 for all outbound traffic. Network Topology : CE1 (connected to ISP1): 10.0.1.1/30 CE2 (connected to ISP2): 10.0.2.1/30 iBGP Router (Internal) connected to both CE1 (10.0.1.2/30) and CE2 (10.0.2.2/30). Configuration on CE1 (Higher Local Preference) : Create a route map to set the local preference to 200 for routes learned from CE1: route-map SET_LOCAL_PREF permit 10 set local-preference 200 In the BGP configuration for CE1, apply this route map to the neighbor: router bgp 65001 ne...
Post a Comment
Read more

BGP MED: Managing Inbound Traffic with Multi-Exit Discriminator

The Multi-Exit Discriminator (MED) is used in BGP to control inbound traffic into your AS. It tells a neighboring AS which entry point into your network it should prefer when there are multiple links between your AS and the neighboring AS. The lower the MED value , the more preferred the path. MED is only honored between the same neighboring AS . Example Scenario : You are connected to ISP1 via two routers, CE1 and CE2 , and want to control which router ISP1 uses to send traffic into your AS. Network Topology : CE1 (connected to ISP1): 10.0.1.1/30 CE2 (connected to ISP1): 10.0.2.1/30 iBGP Router (Internal) connected to both CE1 (10.0.1.2/30) and CE2 (10.0.2.2/30). Configuration on CE1 (Lower MED, More Preferred) : Create a route map to set the MED to 50 for CE1: route-map SET_MED permit 10 set metric 50 Apply this route map to the neighbor in the BGP configuration for CE1: router bgp 65001 neighbor 10.0.1.1 remote-as 65000 neighbor 10.0.1.1 route-map SET_MED out Configuratio...
Post a Comment
Read more