Thursday, August 14, 2014

Apache forbidden message for files with underscore

In my automation server for my cisco equipament, after reboot, things stopped working with apache. After some time troubleshooting I found out that images with underscore in the file name would be forbidden while images wihout would be shown by apache. Really strange!

After trying everything:
- permissions
- directory http files
- etc

The problem was with SELINUX.
Executing echo 0 > /selinux/enforce

To be permanent, do the folling:
On /etc/sysconfig/selinux
change from:
SELINUX=enforcing

to :
SELINUX=disabled

Then, reboot again!
Good luck

Monday, February 11, 2013

Cisco opens up EIGRP

Wow! This is a strange decision from Cisco. So many years closing this protocol to other vendors and now sundently they open it to IETF. I guess that the conclusion is: Now a days, networking market is getting more openned and this is good news for the customers.
http://www.youtube.com/watch?v=o_InjAmW5rI&feature=em-uploademail


Thursday, December 27, 2012

How to interconnect two vrfs in the same switch Catalyst 6500


In a virtualized Data Centre environment, service is provided to customers with isolation in mind using vlans, vrfs and context based services in physical appliances such as firewalls, loadbalancers and Intrusion detection amd also as virtual appliances inside hypervisors.
When this level of virtualization is achieved, it is common that your requirement also increases and some impossible things are demanded. One of these situations are the interconnection of two vrfs in the same switch.
As you know, there can only be one layer3 vlan interface inside a 6500 chassis provided by the supervisor.

The following are solutions to interconnect two vrfs:
  • Use an external firewall or router to route the traffic (bad option)
  • Cross over cable in two ports (Most common)
  • GRE connection between VRFs.
  • Use RD for this requirement
The one that I find more stable is the crossover cable or fiber but it depends on a physical component which can fail.
The most clean solution is the GRE connection, but I have never tested in prodution.

Thursday, December 13, 2012

Redistribute BGP to RIP


In order to redistribute BGP to RIP you will have to specify the metric of the routes when they arrive to rip engine otherwise they will have 255 distance and will not show up in the routing table. By default, the routes will be unreachable.

A examepl below:

router rip
 passive-interface default
 !
 address-family ipv4 vrf bank1
  redistribute bgp 64111 metric 1
  network 192.168.25.0
  neighbor 192.168.25.10
  no auto-summary
  version 2
 exit-address-family

10Gbps interface with Twin-ax cooper cable SFP-H10GB-CU3M

The twin ax cable SFP-H10GB-CU3M appear in a 3750 like this:

Te1/1/1   SERVER    connected    trunk        full    10G SFP-10GBase-CX1


Implement RIP in VRF


It is possible to implement RIP in VRF . Here's an example:


router rip
 passive-interface Vlan1300
 !
 address-family ipv4 vrf client1
  network 192.168.1.0
  no auto-summary
  version 2
 exit-address-family
!

Tuesday, December 11, 2012

Available commands in Cisco IOS


It is possible to browse on available commands in a cisco catalyst or router.
Just type the comand:
show parser dump all

show parser dump all | grep tranceiver

15 debug transceiver detail
15 debug transceiver info
15 debug transceiver error
1 show interfaces transceiver detail module Number
1 show interfaces transceiver detail
1 show interfaces transceiver threshold violations module Number
1 show interfaces transceiver threshold violations
1 show interfaces transceiver calibration module Number
1 show interfaces transceiver calibration
1 show interfaces transceiver properties module Number
1 show interfaces transceiver properties
1 show interfaces transceiver module Number
1 show interfaces transceiver
1 show interfaces transceiver detail module Number
1 show interfaces transceiver detail
1 show interfaces transceiver threshold violations module Number
1 show interfaces transceiver threshold violations
1 show interfaces transceiver calibration module Number
1 show interfaces transceiver calibration
1 show interfaces transceiver properties module Number

SFF8472-5-THRESHOLD_VIOLATION: Rx power high warning; Operating value:


SFF8472-5-THRESHOLD_VIOLATION: Te1/1/1: Rx power high warning; Operating value:  -0.4 dBm, Threshold value:  -1.0 dBm.

This is a strange problem. Normally, fiber problems have high atenuation. This problem ocurres because the signal is too strong, probably due to a fiber cable that is too small Solution: Change the fiber size. If does not work change the SFP.

Friday, December 7, 2012

Cisco ASA Log commands to buffer or logging server


The goal is to force ASA to log a line to buffer or to syslog server when ever a cli command is issued.
One solution is to change the log message 111008 to the level that you want to log in buffer or in trap.

An example:

logging enable
logging timestamp
logging buffer-size 128000
logging monitor alerts
logging buffered alerts
logging trap alerts
logging history alerts
logging facility 15
logging device-id hostname
logging host MGMT 1.1.1.1
logging message 111008 level alerts

Wednesday, December 5, 2012

Traffic generation with 10Gbps ports

This post will detail the test results of throughput traffic between 2 servers with 10Gbps ports.

The results were quite impressive: 10Gbps wire speed!

More update soon!

How to get vlan usage list via SNMP in Nexus 5000 or 7000


The goal is to get the vlans in use from Cisco Nexus but without having a Layer3 associated with it.

Previously, with IOS, The Layer3 and Layer2 vlans where shown when pooling the mib .iso.3.6.1.2.1.2.2.1.2. With Nexus, using the same mib will only pool the interfaces and Layer3 interfaces (SVIs).

Now, with Nexus, currently it is not possible to pool the vlan table with SNMP.

Currently, in a Nexus 5000, this is the output of the snmpwalk:




snmpwalk -v 1 -c public 10.1.1.1 1.3.6.1.2.1.31.1.1.1.1
IF-MIB::ifName.1 = STRING: Vl1
IF-MIB::ifName.2500 = STRING: Vl2500
IF-MIB::ifName.5001 = STRING: Po1
IF-MIB::ifName.10101 = STRING: Gi0/1
IF-MIB::ifName.10102 = STRING: Gi0/2
IF-MIB::ifName.10103 = STRING: Gi0/3
IF-MIB::ifName.10104 = STRING: Gi0/4
IF-MIB::ifName.10105 = STRING: Gi0/5
IF-MIB::ifName.10106 = STRING: Gi0/6
IF-MIB::ifName.10107 = STRING: Gi0/7
IF-MIB::ifName.10108 = STRING: Gi0/8
IF-MIB::ifName.10109 = STRING: Gi0/9
IF-MIB::ifName.10110 = STRING: Gi0/10
IF-MIB::ifName.10111 = STRING: Gi0/11
IF-MIB::ifName.10112 = STRING: Gi0/12
IF-MIB::ifName.10113 = STRING: Gi0/13
IF-MIB::ifName.10114 = STRING: Gi0/14
IF-MIB::ifName.10115 = STRING: Gi0/15
IF-MIB::ifName.10116 = STRING: Gi0/16
IF-MIB::ifName.10117 = STRING: Gi0/17
IF-MIB::ifName.10118 = STRING: Gi0/18
IF-MIB::ifName.10119 = STRING: Gi0/19
IF-MIB::ifName.10120 = STRING: Gi0/20
IF-MIB::ifName.10121 = STRING: Gi0/21
IF-MIB::ifName.10122 = STRING: Gi0/22
IF-MIB::ifName.10123 = STRING: Gi0/23
IF-MIB::ifName.10124 = STRING: Gi0/24
IF-MIB::ifName.10125 = STRING: Gi0/25
IF-MIB::ifName.10126 = STRING: Gi0/26
IF-MIB::ifName.10127 = STRING: Gi0/27
IF-MIB::ifName.10128 = STRING: Gi0/28
IF-MIB::ifName.10129 = STRING: Gi0/29
IF-MIB::ifName.10130 = STRING: Gi0/30
IF-MIB::ifName.10131 = STRING: Gi0/31
IF-MIB::ifName.10132 = STRING: Gi0/32
IF-MIB::ifName.10133 = STRING: Gi0/33
IF-MIB::ifName.10134 = STRING: Gi0/34
IF-MIB::ifName.10135 = STRING: Gi0/35
IF-MIB::ifName.10136 = STRING: Gi0/36
IF-MIB::ifName.10137 = STRING: Gi0/37
IF-MIB::ifName.10138 = STRING: Gi0/38
IF-MIB::ifName.10139 = STRING: Gi0/39
IF-MIB::ifName.10140 = STRING: Gi0/40
IF-MIB::ifName.10141 = STRING: Gi0/41
IF-MIB::ifName.10142 = STRING: Gi0/42
IF-MIB::ifName.10143 = STRING: Gi0/43
IF-MIB::ifName.10144 = STRING: Gi0/44
IF-MIB::ifName.10145 = STRING: Gi0/45
IF-MIB::ifName.10146 = STRING: Gi0/46
IF-MIB::ifName.10147 = STRING: Gi0/47
IF-MIB::ifName.10148 = STRING: Gi0/48
IF-MIB::ifName.10149 = STRING: Gi1/1
IF-MIB::ifName.10150 = STRING: Gi1/2
IF-MIB::ifName.10151 = STRING: Gi1/3
IF-MIB::ifName.10152 = STRING: Gi1/4
IF-MIB::ifName.10201 = STRING: Te1/1
IF-MIB::ifName.10202 = STRING: Te1/2
IF-MIB::ifName.10501 = STRING: Nu0
IF-MIB::ifName.10502 = STRING: Fa0

and the vlans created in Layer2 are:
sh vlan

VLAN Name                             Status    Ports
---- -------------------------------- --------- -------------------------------
1    default                          active    Po1, Eth1/14, Eth1/15, Eth1/16
                                                Eth1/18, Eth1/19, Eth1/20
                                                Eth1/22, Eth1/23, Eth1/24
                                                Eth1/26
2500 MANAGEMENT                       active    Po1
2003 SERVICE A                        active    Po1
2004 SERVICE B                        active    Po1
2005 SERVICE C                        active    Po1
2006 SERVICE D                        active    Po1

Only vlan 1 and 2500 is pooled because have a Layer3 interface.

The test was done in a Nx5k. The same behavior happens for Nexus 7000.

In order to get the vlan list, you will have to walk in another mib:
snmpwalk -v 1 -c public 10..1.1.1 SNMPv2-SMI::enterprises.9.9.46.1.3.1.1.4.1

SNMPv2-SMI::enterprises.9.9.46.1.3.1.1.4.1.1 = STRING: "default"
SNMPv2-SMI::enterprises.9.9.46.1.3.1.1.4.1.2003 = STRING: "SERVICE A"
SNMPv2-SMI::enterprises.9.9.46.1.3.1.1.4.1.2004 = STRING: "SERVICE B"
SNMPv2-SMI::enterprises.9.9.46.1.3.1.1.4.1.2005 = STRING: "SERVICE C"
SNMPv2-SMI::enterprises.9.9.46.1.3.1.1.4.1.2006 = STRING: "SERVICE D"
SNMPv2-SMI::enterprises.9.9.46.1.3.1.1.4.1.2500 = STRING: "MANAGEMENT"






Tuesday, October 30, 2012

service unsupported-transceiver


Some unsupported transceivers can be used in Cisco 3750. Obviously, Cisco wont support it!

c3750(config)#service unsupported-transceiver
 Warning: When Cisco determines that a fault or defect can be traced to
the use of third-party transceivers installed by a customer or reseller,
then, at Cisco's discretion, Cisco may withhold support under warranty or
a Cisco support program. In the course of providing support for a Cisco
networking product Cisco may require that the end user install Cisco
transceivers if Cisco determines that removing third-party parts will
assist Cisco in diagnosing the cause of a support issue.

c3750(config)#

Wednesday, October 17, 2012

Change MTU size in a 3750 port


The Catalyst 3750 cannot change the MTU per port. It can only be done globally in the switch with the command "system mtu 1526". For it to take effect you have to reload the switch.
10/100 ports: Max is 1998
1G: 9000 bytes



C3750#sh system mtu

System MTU size is 1524 bytes
System Jumbo MTU size is 1524 bytes
System Alternate MTU size is 1524 bytes
Routing MTU size is 1500 bytes

Thursday, October 4, 2012

Unable to read configuration. Try again later.


CISCO6500#wr
Unable to read configuration. Try again later.

CISCO6500#


This is caused by high activity on CLI. Probably, a sh run is taking place or any other action that locks the executation of the CLI cmd.

Wednesday, October 3, 2012

high CPU usage on cisco catalyst 6500 with itasca process


In a Cisco 6500 switch with ACE, if the process itasca is consumming too much CPU, it can be caused by logging supervisor command on ACE.

This command will dump the logging of ACE into the supervisor and consumes RP resources.

To resolve this remove the cmd "logging supervisor " from ACE configuration and make ACE send the logging to a log server directly.
 
--------------
 
The same problem was seen with logging generated by the switch itself.
The fix was: 
no logging on

At least, until the problem is found, the cpu was back to normal.

Before:
SWITCH# proc cpu sort
CPU utilization for five seconds: 99%/1%; one minute: 99%; five minutes: 99%
 PID Runtime(ms)   Invoked      uSecs   5Sec   1Min   5Min TTY Process
  62     2749624    243589      11287 86.82% 83.39% 84.82%   0 itasca
 131       11100     21481        516  0.47%  0.60%  0.67%   4 SSH Process
 499   5563701363409673472          0  0.39%  0.44%  0.45%   0 Port manager per
 

After: 
SWITCHh #sh proc cpu sort
CPU utilization for five seconds: 5%/1%; one minute: 9%; five minutes: 30%
 PID Runtime(ms)   Invoked      uSecs   5Sec   1Min   5Min TTY Process
 499   5563783763409717288          0  0.79%  0.94%  0.87%   0 Port manager per
 560     40374923186106614          1  0.31%  0.31%  0.31%   0 HSRP Common
 273   2786680721058539466        263  0.31%  0.36%  0.41%   0 IP Input