Browsing articles tagged with "spanningtree - Admins Goodies"
Apr 3, 2012
tom

Spanning-Tree and redundant links

I have 2 switches which have redundancy between them, meaning fa0/1 on SW1 is connected to fa0/1 on SW2, and fa0/2 on SW1 is connected to fa0/2 on SW2. Both of the switches have the same BID, however the MAC address of SW1 is numerically lower, hence making it the root bridge. Now my question is, on SW2, what determines which of fa0/1 and fa0/2 becomes the RP (Root Port) and the other on blocking […]

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Dec 5, 2011
tom

Netgear GS724T port issue between two switches

We have three 24 port (Gigabit) Netgear GS724T switches which are connected in the following way: SW-003 > SW-001 > SW-002 The port on SW-002 that connects to Sw-003 is constantly flashing once per second, the rest are flickering as the data is transferring as expected. I am concerned that this may mean that we are at risk of exceeding the Gigabit bandwidth between the two switches. If this is the case then I would […]

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Aug 24, 2011
tom

Preventing packet storm on VLAN

I’ve got a connection in a datacenter where the network provider gives me two Ethernet connections. They’re supposedly hooked up to the same VLAN, such that I can wire them up to my switch and only one of them will be active at a time, but either side could then do hardware maintenance (rewiring, switch upgrades, etc.) without causing a service outage. I’ve partitioned my switch off to have a separate VLAN for this external […]

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Aug 23, 2011
tom

Spanning Tree Setup

I understand the basics of spanning tree, but that’s about it. I’m hoping that someone can tell me if this will work as I want it to. I’ve got two Cisco ACE load ballancers setup for redundancy. Each ACE is connected to its own layer 2 switch. Currently each layer 2 switch is connected to its own 1 Gig fibre link to the CoLo. Each fibre link is setup for a different IP Subnet and […]

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Aug 21, 2011
tom

Should the 3Com NJ225 switch implement the spanning tree protocol?

We recently purchased some 3Com IntelliJack NJ225 switches: The specification states that they support IEEE 802.1D, and a mandatory part of this standard is support for the rapid spanning tree protocol. However, we quickly realised that we could not safely create loops when connecting these devices together (using the four “front” ports). After several support calls, 3Com confirmed that they did not implement the RSTP. I think it’s fair to say that we’re not using […]

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Aug 21, 2011
tom

Setting spanning tree link “priorities” in Cisco switches

I’ve got a pair of C2960G-48 switches (running IOS 12.2(46)SE, if it makes a difference) with redundant trunks in place. On these switches there are a bunch of VLANs that carry quite heavy traffic at times (enough to completely saturate the trunks each). I’d like to put in a per-VLAN cross-connected cable to help carry the load and avoid saturating the common trunk. The one thing I’m not sure of is how to prioritise this […]

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Aug 19, 2011
tom

Redundant Ethernet links from a Linux box

This could be an RTFM kind of question. If so, I’ll gladly award the answer to whoever gives a link to TFM In my racks, I’ve got redundancy all over the place. Two sets of switches, two upstream routers, two power paths, dual power supplies in the servers… you know the drill. However, now I’m wondering about dual paths from the servers. Each has two (or more) NICs. What we’ve done in the past was […]

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Aug 16, 2011
tom

Network topology, clearing congestion

Our networking components consist of (3) x D-Link DGS 1248T Switches, and a router. We have 4-5 servers running as VMWare Host, HTTPD, and Storage. The clients on the network are connected to the switches via a patch panel. For the most part, our department requires the most bandwidth to and from the servers. The servers also require significant bandwidth between one another. The clients in the rest of the office however, do not require […]

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Aug 14, 2011
tom

Spanning Tree Portfast in JUNOS

Can someone tell me what the Juniper JUNOS equivalent is for Cisco’s spanning tree portfast command? My google-fu keeps leading me to long whitepapers on Spanning tree and not so much configuration examples. You need to use the Edge command, either by range or per port. edit – here‘s a guide Check more discussion of this question. Bookmark on Delicious Digg this post Recommend on Facebook share via Reddit Share with Stumblers Tweet about it […]

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Aug 14, 2011
tom

Firewall that supports HighAvailability and Spanning Tree

I’m looking for a firewall appliance that supports high availability and spanning tree. I have two ha-cluster nodes and I’d like to protect them with a firewall. To avoid a single point of failure, I’d like to have two ha-capable firewalls. And since I need redundant switches too the firewall must support the spanning tree protocol. My preferred setup: +————+ +———-+ +————–+ lan 1 –| firewall 1 |–| switch 1 |–| ha cluster 1 | […]

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