Monday, July 20, 2015

Cisco USB Console on a Mac

Simple bash script for Cisco USB console. It dynamically inserts device number into screen argument - very handy. Works only for one connected console at a time.

I keep it in my $HOME/bin/cisco-usb-console directory:

#!/bin/bash
PORT=$(ls  /dev/tty.usbmodem*)
exec screen $PORT 9600
Enjoy! :)  

Saturday, January 31, 2015

IOS XR: redistribution of EIGRP routes

Redistribution of EIGRP routes into MP-BGP seems to be very simple process. However, I spent 40 minutes troubleshooting the issue.

Simple scenario, PE-CE EIGRP and MP-BGP in the SP Core

PE Config:
RP/0/0/CPU0:XR1(config)#sh run router bgp
Tue Jan 31 11:53:35.119 PST
router bgp 100
 bgp router-id 19.19.19.19
 address-family vpnv4 unicast
 !
 neighbor 3.3.3.3
  remote-as 100
  update-source Loopback0
  address-family vpnv4 unicast
  !
 !
 vrf VPN_B
  rd 100:2
  address-family ipv4 unicast
   redistribute eigrp core
  !
 !
RP/0/0/CPU0:XR1(config-bgp-vrf-af)#sho run router eigrp
Tue Jan 31 11:53:58.807 PST
router eigrp core
 vrf VPN_B
  address-family ipv4
   autonomous-system 1
   redistribute bgp 100
   interface GigabitEthernet0/0/0/2
   !
  !
According to IOS XR 5.2 Command Reference Guide "redistribute eigrp" syntax is pretty straightforward:
Enhanced Interior Gateway Routing Protocol (EIGRP)
redistribute eigrp process-id [ match { external | internal } ] [ metric metric-value ] [ route-policy route-policy-name ]
no redistribute eigrp process-id [ match { external | internal } ] [ metric metric-value ] [ route-policy route-policy-name
What is the process-id? According to the same reference guide:
process-id
For the eigrp keyword, an EIGRP instance name from which routes are to be redistributed.        

...but I don't see any vpnv4 routes from my PE (19.19.19.19):

R3#sh bgp vpnv4 unicast all summary
BGP router identifier 3.3.3.3, local AS number 100
BGP table version is 75, main routing table version 75
8 network entries using 1216 bytes of memory
8 path entries using 640 bytes of memory
8/8 BGP path/bestpath attribute entries using 1280 bytes of memory
8 BGP extended community entries using 1620 bytes of memory
0 BGP route-map cache entries using 0 bytes of memory
0 BGP filter-list cache entries using 0 bytes of memory
BGP using 4756 total bytes of memory
BGP activity 27/19 prefixes, 31/23 paths, scan interval 60 secs

Neighbor        V           AS MsgRcvd MsgSent   TblVer  InQ OutQ Up/Down  State/PfxRcd
2.2.2.2         4          100     110     128       75    0    0 01:31:51        2
4.4.4.4         4          100     104     126       75    0    0 01:31:38        2
5.5.5.5         4          100     110     125       75    0    0 01:31:40        2
19.19.19.19     4          100      31      40       75    0    0 00:10:41        0

Then I realized that it could be something wrong with process-id - instead of the core I tried to use AS number inside vrf:

vrf VPN_B
  rd 100:2
  address-family ipv4 unicast
   redistribute eigrp 1
   redistribute eigrp core

And it worked!

R3#sh bgp vpnv4 unicast all summary
BGP router identifier 3.3.3.3, local AS number 100
BGP table version is 75, main routing table version 75
8 network entries using 1216 bytes of memory
8 path entries using 640 bytes of memory
8/8 BGP path/bestpath attribute entries using 1280 bytes of memory
8 BGP extended community entries using 1620 bytes of memory
0 BGP route-map cache entries using 0 bytes of memory
0 BGP filter-list cache entries using 0 bytes of memory
BGP using 4756 total bytes of memory
BGP activity 27/19 prefixes, 31/23 paths, scan interval 60 secs

Neighbor        V           AS MsgRcvd MsgSent   TblVer  InQ OutQ Up/Down  State/PfxRcd
2.2.2.2         4          100     115     133       75    0    0 01:36:37        2
4.4.4.4         4          100     109     131       75    0    0 01:36:24        2
5.5.5.5         4          100     115     130       75    0    0 01:36:26        2
19.19.19.19     4          100      36      45       75    0    0 00:30:07        2


Wednesday, January 30, 2013

SP High End Product

We are coming to the IOS XR. Personally, I like this OS and can recommend to start from the IOS XR Fundamentals book.



This post covers following topics:

  1. IOS XR structure
  2. Installing IOS XR software
  3. Upgrade and manage IOS XR software
  4. Secure  Domain Router (SDR)
  5. CRS-1/3 structure
  6. CRS-1/3 multi-chassis
  7. Redundant Router Processors
  8. RP switchover
  9. MSC architecture
  10. Switch Fabric Architecture

Tuesday, January 29, 2013

GE/10GE in the Core

Hi everyone, this post is about ethernet in the core. Yes, it still covering GE/10GE standards and doesn't include 40/100GE. I expect, that it will be covered in CCIE SP version 4. And hopefully, i will try to pass the written v4 for recertification :))

The ethernet topic is usually well known and nobody expects "hard" questions. Anyway I prefer to refresh my memory by using Cisco docs. Maybe I'm missing some Cisco marketing terms (like VTXP in IPoDWDM post), etc. :))



This post includes following topics:
  1. Gigabit Ethernet standards
  2. 10 Gigabit Ethernet standards
  3. Duplex Mode
  4. MTU
  5. Flow control
  6. Link Aggregation Control Protocol
  7. 802.1Q VLAN sub-interface

Monday, January 28, 2013

IPoDWDM

Ok, let's talk about IP over DWDM.



This post includes:

  1. Optical channel payload unit (OPU)
  2. Optical channel data unit (ODU)
  3. Optical channel transport unit (OTU)
  4. Optical channel (OCh)
  5. Shared Risk Link Group (SRLG)
  6. Virtual Transponder (VTXP)
  7. FEC-FRR Triggering
  8. Optical Parameters - Rx-los-threshold, Wavelength and Transmit-power
  9. G.709 Parameters

Long story short:
  • integration of DWDM technology into the router
  • GMPLS-UNI interface from the router to the DWDM network
  • Advanced DWDM control plane - GMPLS/WSON
Supported platforms:
  • CRS-1/3
  • ASR9K
  • 12K
  • 7600
  • or any platform with tunable WDM optics support
References:
  1. IPoDWDM and IP NGN Core Design - deep dive
  2. Cisco Live 2010 (Las Vegas) - IPoDWDM: 40G 100G and Beyond (BRKOPT-2115).
  3. Cisco Live 2012 (London) - Converged Architecture for IP + Optical, multi-Terabit Routing, Control Plane (BRKSPG-2606) - this one is really good overview
  4. White Paper: Converge IP and DWDM Layers in the Core Network
  5. ITU-T G.709: Interfaces for the optical transport network
  6. Wikipedia: G.709
  7. Cisco 7600 ES+ line cards: Configuring IPoDWDM
  8. Configuring Dense Wavelength Division Multiplexing Controllers on Cisco IOS XR Software
  9. Configuring Dense Wavelength Division Multiplexing Controllers on the Cisco ASR 9000 Series Router
  10. Dense Wavelength Division Multiplexing Commands on the Cisco IOS XR Software

Sunday, January 27, 2013

Packet over SONET

I will try to make my posts according to the CCIE Service Provider Written Exam Checklist v3.0.  This post cover the topics in paragraph 1.1. It took me about 10 hours to check all the references.


Packet over SONET

This post includes following topics:
  1. Cisco HDLC(cHDLC) Encapsulation
  2. PPP Encapsulation
  3. Frame-Relay Encapsulation
  4. Maximum Transmission Unit (MTU)
  5. Cyclic Redundancy Check (CRC)
  6. Keepalive Timer
  7. Frame-Relay DLCI on point-to-point sub-interface
  8. SONET Controller
  9. POS Channel
  10. Channelized SONET
  11. SONET APS

References:

  1. A Brief Overview of SONET Technology
  2. Cisco Tech Note: Differences between SDH and SONET
  3. Configuring POS Interfaces on Cisco IOS XR 3.9 Software (CRS-1)
  4. Configuring POS Interfaces on Cisco IOS XR 3.9 Software (XR12K)
  5. Packet-over-SONET Interface Commands on Cisco IOS XR 3.9 Software (XR12000)
  6. Configuring Serial Interfaces on Cisco IOS 12.2 SR Software
  7. Understanding SONET/ SDH

Saturday, January 26, 2013

CCIE-SP Written exam

The 350-029 exam is scheduled  on the next-next week. I have no other choice than to pass it. :)
It took me a long time to schedule it due to various reasons...

Anyway, I will start repeating the materials - especially Cisco-specific stuff like IOS XR, EIGRP, etc.