Having the red alarm led on but nothing is wrong with your JunOS powered Juniper device? First, look out what alarm is triggered by issuing the following command :
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show chassis alarm |
If absolutely nothing is really wrong, you will see the following alarm : Alarm time Class Description 2016-01-20 07:11:59 UTC Major Management Ethernet Link Down… Read More »
Having the following output message while trying to create a VLan outside higher than 1000 on your Cisco device?
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SWITCH-601(config)#vlan 2991 SWITCH-601(config-vlan)#end % Failed to create VLANs 2991 Extended VLAN(s) not allowed in current VTP mode. %Failed to commit extended VLAN(s) changes. |
This mean that you are running VTP mode 1 or 2, which only support VLan range between 1 – 1000. To be able to create anything outside of that scope, you need to run VTP… Read More »
You probably noticed that rapid pings toward a JunOS device result in a loss of packet as the example shown below. In our case we are issuing the ping from a Cisco router : Sending 100, 500-byte ICMP Echos to 10.204.100.1, timeout is 2 seconds: Packet sent with a source address of 10.204.100.1 .!!!!!!!!!.!!!!!!!!!.!!!!!!!!!.!!!!!!!!!.!!!!!!!!!.!!!!!!!!!.!!!!!!!!! .!!!!!!!!!.!!!!!!!!!.!!!!!!!!!… Read More »
As a long time OpenVPN user, the major annoyance I faced with this software is obviously the inflexible behaviour of the Windows client, which is just fine if you are running/connecting to a remote server. However, if you are actively managing thousand servers and networks, you may end up at some point having the need to… Read More »
Here is a chart for the various DWDM optic channels below. Wavelenght band overview : O-Band : 1270nm to 1370nm E-Band : 1371nm to 1470nm S-Band : 1471nm to 1530nm C-Band : 1531nm to 1570nm L-Band : 1571nm to 1611nm Channel Wavelength (nm) Frequency (THz) 72 (DWDM Channel C72) 1520,25 197,20 71 (DWDM… Read More »
If you have a Cisco ASR or smaller service router, you probably noticed that the device have a dedicated management interface. This special interface is a mapped to a Vritual Routing and Forwarding (VRF) instance. VRF allow multiple routing tables to coexist within the same router. You will first ensure that you have the VRF… Read More »
If you have a Ex4200 unit in hand that was pulled out from a virtual chassis stack, configured as linecard (LC), you may want to convert it back to “routing-engine” (RE) for future usage. I would suggest first to reset the unit to factory default (in CLI mode) :
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load factory-default set system root-authentication plain-text-password |
Apply the change :
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commit |
Did you get the following output trying to set a port in trunk mode on a Cisco IOS powered switch? SWITCH(config-if)#switchport mode trunk Command rejected: An interface whose trunk encapsulation is “Auto” can not be configured to “trunk” mode. This is because you are missing the encapsulation type (likely to be 802.1Q) on that port.… Read More »
In some rare occasion, you may be unable to access the OpenVPN WebUI through the standard port tcp-943 after a brand new installation. In my particular case, it happened once with CentOS 7. This is caused by the init script that does not ran properly. To resolve this matter, just invoke the init script manually… Read More »
Here is how to remotely copy your Brocade device running FabricOS to a remote TFTP server. To copy the currently running configuration :
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copy startup-config tftp <TFTP_Server_IP> startup-config.cfg |
To copy the configuration saved to the flash memory :
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copy run tftp <TFTP_Server_IP> switch-name.cfg |
To restore the remote config to your device :
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copy tftp start <TFTP_Server_IP> switch-name.cfg |