Tag Archives: Cisco Switch

My IPv6/Routing/Cisco Lab Rack (2019)

2019-06-24Memorandum, Off-Topic19", CCNA, CCNP, Cisco Router, Cisco Switch, Internet, Juniper SA, Juniper ScreenOS, Juniper SRX, Juniper SSG, Palo Alto Networks, PoE, Raspberry Pi, VPN, WebcamJohannes Weber

My lab rack of 2019 consists of multiple Cisco routers and switches, as well as Juniper ScreenOS firewalls for routing purposes, a Palo Alto Networks firewall, a Juniper SRX firewall, a server for virtualization and some Raspberry Pis. That is: This rack can be used for basic Cisco courses such as CCNA or CCNP, or for even bigger BGP/OSPF or IPsec VPN scenarios since those ScreenOS firewalls are perfect routers as well. Of course, everything is IPv6 capable. Having some PoE-powered Raspberry Pis you can simulate basic client-server connections. A Juniper SA-2500 (aka Pulse Connect Secure) for remote accessing the Lab rounds things up.

I am just writing down a few thoughts on why I have “designed” the rack in that way. It’s basically a reminder for myself. ;)

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NTP Authentication on Cisco IOS

2019-05-17Authentication, Cisco Systems, NTPAuthentication, Cisco Router, Cisco Switch, MD5, NTPJohannes Weber

This is how you can use NTP authentication on Cisco IOS in order to authenticate your external NTP servers respectively their NTP packets. Though it is not able to process SHA-1 but only MD5, you’re getting an authentic NTP connection. Let’s have a look:

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My CCNP TSHOOT Lab: The Overall Picture

2018-11-12Cisco Systems, IPv6, RoutingAuthentication, CCNP, Cisco Router, Cisco Switch, Dynamic Routing, EEM, FHRP, GLBP, GRE, IPv6, MD5, NTP, prefix-list, route-map, VRRPJohannes Weber

During the last few weeks I published a couple of blogposts concerning routing protocols such as BGP, OSPFv3, and EIGRP. (Use the “Cisco Router” tag on my blog to list all of them.) They are all part of my current Cisco lab that I am using for my CCNP TSHOOT exam preparation. While I depicted only the details of the routing protocols in those blogposts, I am showing my overall lab with all of its Cisco IOS configs here. Just to have the complete picture. There are a couple of not-yet-blogged configs such as VRRP, GLBP, NTP authentication, embedded event manager (EEM), or route-maps and distribute/prefix lists though.

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Using Cisco’s IOS Archive

2018-11-06Cisco Systems, Network, Tutorial/HowtoArchive, Cisco Router, Cisco Switch, Reload, Rollback, SCP, TFTPJohannes Weber

Cisco’s IOS offers an easy to use feature for configuration versioning to an external server such as TFTP or SCP. Furthermore, you can use IOS commands to compare any two snapshots and to roll back to one of them.

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Basic Cisco Configuration

2017-05-09Cisco Systems, Design/Policy, TemplateACL, bogons, CCNP, Cisco Router, Cisco Switch, CLI, DHCP, From Scratch, IPv6, NAT, NTP, PAT, SNMP, SSH, Syslog, Template, uRPF, vtyJohannes Weber

Following is a list of the most common Cisco device configuration commands that I am using when setting up a router or switch from scratch, such as hostname, username, logging, vty access, ntp, snmp, syslog. For a router, I am also listing some basic layer 3 interface commands, while for a switch I am listing STP and VTP examples as well as the interface settings for access and trunk ports.

This is not a detailed best practice list which can be used completely without thinking about it, but a list with the most common configurations from which to pick out the ones required for the current scenario. Kind of a template. Of course with IPv6 and legacy IP.

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CCNP SWITCH Lab show commands

2017-04-19Cisco Systems, SwitchingAdjacency, ARP, CCNP, CDP, Cisco Router, Cisco Switch, DHCP, DTP, EtherChannel, HSRP, IP SLA, LACP, LLDP, MAC Address, NTP, PoE, Port Security, SDM, SNMP, STP, TCAM, UDLD, VLAN, VTPJohannes Weber

Second post of this little series. While I was using my CCNP SWITCH lab for testing many different protocols, I “showed” and saved the output of those protocols as well. Refer to the lab overview of my last post in order to understand those outputs.

I basically saved them as a reference for myself in case I am interested in the information revealed by them. I won’t explain any details of the protocols nor the outputs here. Just many listings. Fly over them and reflect yourself whether you would understand anything. ;) Here we go:

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Wireshark Layer 2-3 pcap Analysis w/ Challenges (CCNP SWITCH)

2017-03-29Cisco Systems, Routing, SwitchingARP, CCNP, CDP, Challenge, Cisco Router, Cisco Switch, DHCP, DNS, DTP, HSRP, ICMP, ICMPv6, IP SLA, IPv6, LACP, LLDP, MAC Address, NTP, pcap, RIP, SNMP, SSH, STP, Syslog, TFTP, UDLD, VLAN, VTP, WiresharkJohannes Weber

While preparing for my CCNP SWITCH exam I built a laboratory with 4 switches, 3 routers and 2 workstations in order to test almost all layer 2/3 protocols that are related to network management traffic. And because “PCAP or it didn’t happen” I captured 22 of these protocols to further investigate them with Wireshark. Oh oh, I remember the good old times where I merely used unmanaged layer 2 switches. ;)

In this blogpost I am publishing the captured pcap file with all of these 22 protocols. I am further listing 46 CHALLENGES as an exercise for the reader. Feel free to download the pcap and to test your protocol skills with Wireshark! Use the comment section below for posting your answers.

Of course I am running my lab fully dual-stacked, i.e., with IPv6 and legacy IP. On some switches the SDM template must be changed to be IPv6 capable such as sdm prefer dual-ipv4-and-ipv6 default .

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Layer 2 Redundancy with STP: Palo Alto Firewall + Cisco Switches

2013-10-30Cisco Systems, Palo Alto Networks, SwitchingCisco Catalyst 2950, Cisco Switch, Palo Alto Networks, Spanning Tree Protocol, STPJohannes Weber

I built a basic test laboratory with a Palo Alto Networks PA-200 firewall and two Cisco Catalyst 2950 switches in order to test the Spanning Tree Protocol (STP) for achieving Layer 2 redundancy for the physical connections to/from the firewall. This post lists the configurations, “show spanning-tree” outputs from the switches and a few other outputs after several tests. Not all tests ran without any problems so I think there must be something wrong with my configurations, the test sequences, with the STP process, or with the MAC address tables. Maybe some readers have similar experiences?

[UPDATE] Problem solved! I missed the layer 2 zones. Description at the bottom. [/UPDATE]

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