Monthly Archives: May 2021

Getting mac-address table from Fortiswitch

Tracking down MACs from a switch can be very beneficial. You can use the information from the MAC table to track down where a device is plugged into, or if there is some kind of loop in the network.

This command is used from the Fortigate to drill down to the Fortiswitch. I do believe it would also work directly from the Fortiswitch.

To display the whole routing table:

diagnose switch-controller switch-info mac-table

Lets say I need to look for the last 4 of the MAC to find exactly where this device plugs into.

diagnose switch-controller switch-info mac-table | grep 3a:fe

00:60:6e:ec:3a:fe port1 1

Now we can see that device is plugged into port 1 of the switch.

Dell N2248-ON firmware restore from ONIE Recovery

I have been working a lot with the Dell N-series over last few years, and now the N2248-ON which can run OS10 as well as the default OS6. We upgraded firmware to the latest 6.6.3.10 and all seemed to go well. Somehow it did not and hosed both primary/secondary firmware. The device was boot looping – the only option was to drop into ONIE Recovery and re-install the firmware. Here are the steps I used:

The ONIE recovery area runs a version of Linux. First check out your NIC to make sure it finds it:

ONIE:/ # ifconfig
eth0 Link encap:Ethernet HWaddr 8C:47:BE:97:B5:0F
inet6 addr: fe80::8e47:beff:fe97:b50f/64 Scope:Link
UP BROADCAST RUNNING MULTICAST MTU:1500 Metric:1
RX packets:67 errors:0 dropped:0 overruns:0 frame:0
TX packets:13 errors:0 dropped:0 overruns:0 carrier:0
collisions:0 txqueuelen:1000
RX bytes:6904 (6.7 KiB) TX bytes:1198 (1.1 KiB)
Memory:dfe00000-dfe7ffff

Great! Eth0 is found, but of course link status is down. Eth0 is the out of band management interface. We should be able to set an IP address on the interface and install firmware VIA TFTP or USB.

First I will setup and IP that can communicate with my laptop :

ifconfig eth0 192.168.1.100 netmask 255.255.255.0

ONIE:/ # ifconfig
eth0 Link encap:Ethernet HWaddr 8C:47:BE:97:B5:0F
inet addr:192.168.1.100 Bcast:192.168.1.255 Mask:255.255.255.0
inet6 addr: fe80::8e47:beff:fe97:b50f/64 Scope:Link
UP BROADCAST RUNNING MULTICAST MTU:1500 Metric:1
RX packets:108 errors:0 dropped:0 overruns:0 frame:0
TX packets:49 errors:0 dropped:0 overruns:0 carrier:0
collisions:0 txqueuelen:1000
RX bytes:10874 (10.6 KiB) TX bytes:7658 (7.4 KiB)
Memory:dfe00000-dfe7ffff

Perfect! My laptop is 192.168.1.99 – and connected directly to the out of band MGMT port.

Next we will TFTP the file up. This file is located in the software archive you download from Dell – Its located in the
“Otherfiles” folder. In this case the file name is onie-installer-x86_64-dellemc_n22xx_6.6.3.10. Next I put this on my TFTP server and we can start the install.

First lets turn off the ONIE-Discovery attempts with the onie-stop command.

Now lets upgrade – Run:

onie-nos-install tftp://192.168.1.99/onie-installer-x86_64-dellemc_n22x
x_6.6.3.10

The onie-nos-install will install the OS back to the device. The firmware took a few minutes to install, with about 4 reboots I think – it was all automatic.

Now lets see if the switch was updated with the “show version” command.

All is good!