Month: October 2018

OSPF Point to Point vs Point to Multipoint Router LSA difference

OSPF Point to Point vs Point to Multipoint Router LSA difference

Below is Router 4’s LSA when it is configured as a Point to Point connection on an Ethernet network. Link connected to: a Stub Network (Link ID) Network/subnet number: 10.2.4.0    *****CHANGED**** (Link Data) Network Mask: 255.255.255.0      *****CHANGED**** Number of MTID metrics: 0 TOS 0 Metrics: 10                                                     *****CHANGED****   This is the same router but if…

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IPv6 new book and First Hop Routing Protocols

IPv6 new book and First Hop Routing Protocols

I recently found out there is a newer IPv6 book that came out recently.  Most of the previous books I read were older version that still had the Site Local Addresses which has been depreciated. Here is a link to the book. http://www.ciscopress.com/store/ipv6-fundamentals-a-straightforward-approach-to-understanding-9781587144776   There are some gaps that are not covered in it but…

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Who doesn’t need a little PPPoE love in their day

Who doesn’t need a little PPPoE love in their day

In the following blog I will be configuring PPPoE with the constraints in the drawing.   R1 Configuration R1#config t Enter configuration commands, one per line. End with CNTL/Z. R1(config)#ip local pool TEMP 10.1.1.10 10.1.1.254 R1(config)#interface virtual-template 2 R1(config-if)#ip address 10.1.1.1 255.255.255.0 R1(config-if)#peer default ip address pool TEMP R1(config-if)#exit R1(config)#bba-group pppoe GROUP1 R1(config-bba-group)# *Oct 29…

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Integrated Routing and Bridging or IRB

Integrated Routing and Bridging or IRB

Concurrent Routing and Bridging (CRB) was the original form which allowed either Routing or Bridging on the same interface but not on both.   This has been since been replaced with Integrated Routing and Bridging (IRB).  IRB adds some additional features such as Routing and Bridging on the same interface. IRB uses a Bridged Virtual Interface…

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Where, oh where has the VLAN information gone? VTP and how it impacts the VLAN Database.

Where, oh where has the VLAN information gone? VTP and how it impacts the VLAN Database.

This is a topic we learn in the first few days of learning about Cisco.  However, in the normal day to day life we rarely have to think about this information. We usually do remember the vlan.dat file is stored in the nvram.  What we don’t remember is what kinds of impact the VTP version…

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MPLS VPNV4 with and Without BGP IPv4 Default Unicast Routing

MPLS VPNV4 with and Without BGP IPv4 Default Unicast Routing

I have labbed up an MPLS network to do some captures of what the configurations look like both with and without Unicast BGP default enabled.  Including packet captures.  RR is a router reflector.  R2 is configured to have Default BGP IPv4 Unicast Routing turned on.  R3 is configured to have Default BGP IPv4 unicast routing…

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Two great IPv6 Goodies

Two great IPv6 Goodies

If you are not familiar with IPv6 it works slightly differently then IPv4 when it comes to troubleshooting.  One of the issues I ran into is that I depend on ARP often when dealing with Layer 2/3 issues.  ARP as we know it in IPv4 doesn’t exist in IPv6.  Instead it uses a part of…

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Great Free Todo App

Great Free Todo App

I just started using this and it seems pretty awesome so far! Link to site https://trello.com A short video showing some capabilities And some hacks for it  

VRF and Telnet or SSH

VRF and Telnet or SSH

These commands is totally not intuitive but it is very important if you have one or more VRF’s and must telnet or SSH across it.  You can find much more information here: https://www.cisco.com/c/en/us/support/docs/ip/telnet/200718-Configure-Telnet-SSH-Access-to-Device-wi.html Cisco does change their paths so just search for “Cisco Telnet VRF”. Here is a discussion at the CLN. The command for…

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