An Introduction to the Force10 S25N

In September I had the honor of attending Gestalt IT's first Networking Tech Field Day, where a dozen of us bloggers got to talk with engineers from several prominent networking companies. One of these companies was Force10 Networks, which specializes in high-throughput (10G+) Ethernet switching and routing. Force10 has generously sponsored one of their products, an S25N datacenter switch for the community lab, and I hope to have it available for public use in the next week or so.

Similarities to Cisco IOS

To get acquainted with the device, I walked through the quick start guide. The first thing I noticed, as anyone with Cisco experience will, is that the CLI interface to Force10's operating system, FTOS, is very similar to Cisco's IOS. This is great, as it greatly reduces the learning curve for anyone with prior experience configuring IOS. Some similarities include:

• Three CLI modes (exec, privileged exec, configuration)
• Question mark for context-sensitive help
• Tab auto-completion
• UNIX-like shortcut keys (up arrow, ctrl+a, ctrl+e, etc.)
• Use of the preceding keyword no to negate commands
• The show command is used to glean information
• Output filtering with the pipe character
• The do command is used to issue exec commands from configuration mode
• Running and startup configurations

Here's an example of the CLI as accessed from a freshly-booted switch:

Force10>
Force10> ?
disable                         Turn off privileged commands            
enable                          Turn on privileged commands             
exit                            Exit from the EXEC                      
ip                              Global IP subcommands                   
monitor                         Monitoring feature                      
quit                            Exit from the EXEC                      
show                            Show running system information         
ssh                             Open a SSH connection                   
ssh-peer-stack-unit             Open a SSH connection to the peer Stack-unit
tdr-cable-test                  Start diagnostics (TDR test) for the cable
telnet                          Open a telnet connection                
telnet-peer-stack-unit          Open a telnet connection to the peer Stack-unit
terminal                        Set terminal line parameters            
test                            Test function                           
traceroute                      Trace route to destination              
Force10> enable
Force10#00:20:51: %STKUNIT0-M:CP %SEC-4-ENABLE_PASSW_NOT_CONFIGURED: Enable password is required for authentication but not configured
00:20:51: %STKUNIT0-M:CP %SEC-3-AUTHENTICATION_ENABLE_SUCCESS: Enable password authentication success  on console

Force10# configure
Force10(conf)# hostname MyFirstS25
MyFirstS25(conf)# interface g0/1
MyFirstS25(conf-if-gi-0/1)# description Bldg 123
MyFirstS25(conf-if-gi-0/1)# ip address 192.168.0.1/24
MyFirstS25(conf-if-gi-0/1)# ipv6 address 2001:db8:0:f10::1/64
MyFirstS25(conf-if-gi-0/1)# no shutdown
MyFirstS25(conf-if-gi-0/1)#

Observe that the above commands are nearly identical to Cisco IOS, with the exception that the subnet mask for the IPv4 interface address is specified in CIDR notation rather than dotted-decimal (though I'm guessing that this is not an unwelcome change for most of us). FTOS also sports a handy command which allows you to view the configuration of an interface quickly, directly from interface configuration mode:

MyFirstS25(conf-if-gi-0/1)# show config
!
interface GigabitEthernet 0/1
 description Bldg 123
 ip address 192.168.0.1/24
 ipv6 address 2001:db8::1/64
 ipv6 address 2001:db8:0:f10::1/64
 no shutdown

Look familiar? In fact, the entire configuration of the device might easily be mistaken for an IOS configuration at first glance:

MyFirstS25# show running-config
Current Configuration ...
! Version 8.3.2.0
! Last configuration change at Thu Jan  2 00:19:22 1997 by default
!
redundancy auto-synchronize full
!
hardware watchdog
!
hostname MyFirstS25
!
protocol spanning-tree pvst 
 no disable 
!
stack-unit 0 provision S25N
!
interface GigabitEthernet 0/1
 description Bldg 123
 ip address 192.168.0.1/24
 ipv6 address 2001:db8::1/64
 ipv6 address 2001:db8:0:f10::1/64
 no shutdown
!
interface GigabitEthernet 0/2
 no ip address
 shutdown
!
...
!
interface GigabitEthernet 0/24
 no ip address
 shutdown
!
interface Vlan 1
!       
line console 0
 logging synchronous level 2 limit 20
line vty 0
line vty 1
line vty 2
line vty 3
line vty 4
line vty 5
line vty 6
line vty 7
line vty 8
line vty 9
!
end

Some Fundamental FTOS Configuration

Given that we already know so much of FTOS' configuration syntax thanks to IOS, let's look at some FTOS-specific syntaxes.

One aspect of configuration that's quite different under FTOS is VLAN assignment for both trunking and access ports. Assignment of a physical interface to a VLAN is done under VLAN interface (SVI) configuration, after setting the appropriate physical interface(s) to L2 mode with the switchport command. This is opposite of the IOS approach, where VLANs are assigned under interface configuration.

MyFirstS25(conf)# interface g0/2
MyFirstS25(conf-if-gi-0/2)# switchport
MyFirstS25(conf-if-gi-0/2)# interface vlan10
MyFirstS25(conf-if-vl-10)# untagged g0/2
MyFirstS25(conf-if-vl-10)# untagged g0/3
% Error: Port is not in Layer-2 mode Gi 0/3.
MyFirstS25(conf-if-vl-10)#

Note that we cannot assign an interface to a VLAN until we have designated it as a layer two port; all interfaces operate at layer three by default interfaces must be designated as either switched or routed before they may pass traffic (thanks Venkat). IEEE 802.1Q trunks are defined in a similar manner, with the tagged command.

interface Vlan 11
 no ip address
 tagged GigabitEthernet 0/13
!
interface Vlan 12
 no ip address
 tagged GigabitEthernet 0/13
!
interface Vlan 13
 no ip address
 tagged GigabitEthernet 0/13

This may take a moment to wrap one's head around, and (for now, at least) I think I prefer the IOS approach. At any rate, expect to see some articles featuring Force10's FTOS in the near future. Oh, I almost forgot to save my configuration. Hmm, I wonder if that's the same as IOS too...

MyFirstS25# copy run start
File with same name already exist. 
Proceed to copy the file [confirm yes/no]: y
!
2467 bytes successfully copied

Yep. (By the way, write also works, and doesn't prompt for confirmation.)