Category Archives: Networking

Possible Reasons for LAN Traffic Congestion

Posted on July 30, 2011 by Humair

If you are experiencing slowness on your LAN here are some possible reasons that you can investigate:

Posted in Networking | Tagged broadcast storms, failing router, failing switch, LAN slowness, LAN traffic congestion, low bandwidth, network issues, network loops, network slowness, networking, Reasons for LAN Traffic Congestion, slow, Traffic Congestion | Leave a comment

Useful FTOS “show” commands

Posted on July 20, 2011 by Humair

There are several FTOS “show” commands that can provide very useful information regarding Force10 Networks switches/routers. I have outlined a number of these very useful commands with a short description of each below. However, keep in mind that although most … Continue reading →

Posted in Force10 Networks, Networking | Tagged Force10, Force10 FTOS, Force10 Networks, Force10 show commands, Force10 switches, FTOS, show, show bootvar, show commands, show environment, show inventory, show linecard, show redundancy, show rpm, show sfm, show version, switches | Leave a comment

Port Monitoring on Force10 Switches

Posted on July 15, 2011 by Humair

In this lab I will demonstrate how to do port monitoring on Force10 switches and capture the packets using a network protocol analyzer (Wireshark in this case). Port monitoring allows the copying of all incoming/outgoing packets on a specific port … Continue reading →

Posted in Force10 Networks, Labs, Networking | Tagged Force10, Force10 switch, Force10 switches, network protocol analyzer, packet analyzer, Packet Sniffer, Packet Sniffing, Port Mirroring, Port Monitoring, Sniffer, VRRP, wireshark | 1 Comment

Setup VRRP with Force10 Switches

Posted on July 12, 2011 by Humair

In this lab I setup Force10 switches with Virtual Router Redundancy Protocol (VRRP). VRRP is a redundancy protocol used to eliminate a single point of failure between a gateway and its respective hosts within the same subnet. I use three … Continue reading →

Posted in Force10 Networks, Labs, Networking, Protocols | Tagged E1200, Force10, Force10 E1200, Force10 Networks, Force10 S55, Force10 S60, FTOS, gateway, gateway redundancy, redundancy protoco, S55, S60, virtual address, virtual IP, Virtual Router Redundancy Protocol, VRRP, VRRP group | 2 Comments

Setting up Cisco EtherChannels – Static, PAgP, and LACP

Posted on June 2, 2011 by Humair

In this lab I used a Cisco Catalyst WS-C3750G-24TS switch [IOS 12.2(25)SEE3] and a Cisco Catalyst WS-C3560G-24TS switch [IOS 12.2(40)SE]. I also physically connected GigabitEthernet 1/0/17 on the Catalyst 3750G to GigabitEthernet 0/17 on the Catalyst 3560G; I did the … Continue reading →

Posted in Cisco, Labs, Networking, Protocols | Tagged Cisco, Cisco Catalyst, Cisco Catalyst WS-C3560G-24TS, Cisco Catalyst WS-C3750G-24TS, etherchannel, LACP, PAgP, port channel, static etherchannel | 1 Comment

Cisco Port Security with Dynamic MAC Address Learning

Posted on May 31, 2011 by Humair

In this lab I used a Cisco Catalyst WS-C3560G-24TS switch [IOS Version 12.2(40)SE]. Using Cisco Port Security it is possible to associate a static MAC address to a physical port on a switch. This only allows one host with that … Continue reading →

Posted in Cisco, Labs, Networking, Technology | Tagged Cisco, Cisco Catalyst 3560 switch, Cisco Catalyst WS-C3560G-24TS, Cisco Port Security, Cisco Port Security with Dynamic MAC Address Learning, Dynamic Port Security, MAC address, Port Security, router, switch, switchport port-security, switchport port-security violation | 4 Comments

How to Fix – Force10 S4810 Switch Stuck in Boot Loop

Posted on May 27, 2011 by Humair

In this blog I discuss how to fix a common boot loop problem. A boot loop can occur if you change the boot variables for a switch and accidentally put in incorrect information. You may also make a typo when … Continue reading →

Posted in Force10 Networks, Networking, Technology | Tagged boot loop, boot variables, Force10, Force10 S4810, FTOS, S4810, TFTP | 2 Comments

pNIC, vNIC, and vmNIC Confusion

Posted on May 26, 2011 by Humair

I have been using both remote desktop and vSphere Client quite often lately. Yesterday, I had a remote desktop session with a Windows Server 2003 physical server and also had vSphere Client (connected to an ESXi server) open with a … Continue reading →

Posted in Networking, Technology, Virtualization and Cloud Computing | Tagged ESXi, ESXi Server, hypervisor, physical NIC, pNIC, remote connection, Remote Desktop, virtual machine, virtual NIC, virtualization, VM, vmNIC, vmware, vNIC, vSphere Client | 5 Comments

Functionality of Layer 2 Switches/Bridges

Posted on May 26, 2011 by Humair

Layer 2 switches and bridges switch frames on a network while layer 3 routers route packets between networks. I once heard a network engineer being asked if a network can be made faster if the network is optimized to use … Continue reading →

Posted in Networking, Technology | Tagged Address Learning, application specific integrated circuits, ASICs, bridges, bridging technologies, broadcasts, Cisco, collision domain, collision domains, datalink layer, filter table, Forward/Filter Decisions, frame, frame filtering, frames, layer 2 broadcasts, Layer 2 Switching, Loop Avoidance, MAC, MAC address, MAC address table, MAC database, Media Access Control, Media Access Control Address, multicasts, network, network layer, network loops, networking, packet, packets, routers, slow convergence, Spanning Tree Protocol, STP, switches, switching | 2 Comments

Setup SSH Access on Cisco Switches

Posted on May 20, 2011 by Humair

The Cisco Catalyst WS-C3750G-24TS [IOS 12.2(25)SEE3] switch provides both layer 2 and layer 3 functionality. In this lab I’m going to demonstrate how to setup SSH access to the switch. The first thing I do is set a hostname and … Continue reading →

Posted in Cisco, Labs, Networking, Technology | Tagged Catalyst, Cisco, Cisco Catalyst 3570, Cisco Catalyst WS-C3750G-24TS, default route, router, SSH, switch | Leave a comment