Skip to main content

Capture Cisco CSR packets and Examine with Wireshark


As you know the Cisco’s Cloud Services Router is a virtual router either installed and configured in public Clouds like Amazon Web Services, AWS, or in your private cloud hosted locally. I needed to capture and monitor the traffic on its interfaces with Wireshark. One way I could found is to capture your desired traffic on any interface of CSR, export it to your local disk and open it with Wireshark.
The following procedure can also be used to capture packets on other physical Cisco Routers running following IOS versions.
Cisco IOS Release 12.4(20)T or later
Cisco IOS-XE Release 15.2(4)S – 3.7.0 or later
Lets start capturing traffic here on Cisco CSR.
First we specify the interface to capture the packets on;
csr#monitor capture GIG2 interface GigabitEthernet 2 both
Here GIG2 is any name to create a file and store packets in it, both means to capture both inbound and outbound packets on interface gigabitethernet 2
You can specify ipv4 or ipv6 traffic, select protocol or even sepcify ACL to capture only selected traffic with following command;
csr#monitor capture GIG2 match ipv4 protocol tcp any any
Now we Start the capturing packets on our selected criteria as configured above
csr#monitor capture GIG2 start
The capture is now active. Allow it to collect the necessary data.
After capturing sufficient packets, Stop the capture:
csr#monitor capture CAP stop
Now either you can examine the capture in a summary or detailed view on CSR router itself or export it to your local computer disk and examine with Wireshark.
To examine the capture in a summary view:
csr#show monitor capture CAP buffer brief
Examine the capture in a detailed view:
csr#show monitor capture CAP buffer detailed
Export the capture in PCAP format for further analysis:
csr#monitor capture GIG2 export tftp://10.0.1.11/GIG2.pcap
Once the necessary data has been collected, and exported to tftp server, remove the capture:
csr#no monitor capture GIG2


Comments

Popular posts from this blog

What is Cisco Supervisor Engine?

Supervisor Engine is a module that is installed in the Cisco Chassis-based Catalyst Switches or Routers. Supervisor engine contains nearly all the same components of a fixed Cisco Switches or Routers. These Supervisor engines come in a variety of different types with different functionalities and are installed in the Switches/Router Chassis as per requirements of the network types.

Benefits of Supervisor Engines
By installing Latest Supervisor Engines in your existing investments (Switches and Routers) you can scale system performance and integrate next-generation services into your Networks.
Within a single multilayer switch chassis, two supervisor modules with integrated route processors can be used to provide hardware redundancy. If an entire supervisor module fails, the other module can pick up the pieces and continue operating the switch.
The supervisor engine contains the following integrated daughter cards that perform forwarding and routing and provide the protocols supported …

GNS3 Docker Error while creating node: Docker has returned an error: Cannot connect to host docker:80

Error while creating node: Docker has returned an error: Cannot connect to host docker:80 ssl:False [No such file or directory]

After adding docker template for Alpine Linux in gns3, you get above mentioned message when you want to use alpine linux in GNS3.

To get rid of this message you have to install Docker by following below link
curl -fsSL https://get.docker.com/ | sh

If you do not have curl installed then instal curl first with below command.apt-get install curl
After installing Docker you need to add your user name in the docker group with the following command. $ sudo usermod -aG docker your_username

Verify if the docker service is started with following command$ service docker status
If docker is not started then start with following command $ sudo service docker start
Logout from GNS3 Virtual Machines and log back. Start gns3 and use alpine linux.

a file I/O error has occurred while accessing vmware converter

While converting physical Windows 7 machine to Virtual machine of infrastructure type, I got this error. The error seems it is unable to read/write source or destination datastore.

I have installed VMware-converter-en-6.2.0-8466193 on Windows 7 physical machine with option locally selected. (not at server/client option)

All of my ESXi servers are connected to the vCenter Server, so I had to use vCenter Server's IP address to send this physical machine to the virtual world.

The issue i found was with the dns resolution to the vCenter Server's hostname. Since I am not using the same dns server on the Windows 7 client machine. So I updated the host entries manually for the vCenter Server's hosname to it IP address.

After adding dns eteries to the hostfile of windows 7, I am not getting this "a file I/O error has occurred while accessing vmware converter" and the migration has started.