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Warren P
Asked: 2010-04-13 09:32:08 +0800 CST

How long do managed gigabit ethernet switches take to boot up?

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One critical drawback that I have found in researching managed-switches, and one that I have some past experience with is that anything with "lots" of firmware is going to have lots of issues associated with that firmware.

We are in the middle of researching rackmount gigabit switches (48 port). It looks like for 48 ports, our only choice is managed switches (Dell, Cisco/Linksys,HP, etc). What I want to know, that I can not find out much about is the boot-time for various managed switches.

If you own one, can you please answer with the model number, and the cold boot time in seconds. I have read online that Linksys (now Cisco) SRW series sometimes take almost 5 minutes before they are fully booted up, and that is an unacceptable cost for us.

I particularly want to know about Dell PowerConnect managed switch bootup time (model 3548 and 5448), and would like to confirm the 5-minute boot time on the SRW2048 or similar model, and any HP ProCurve boot up times.

The composite of all those figures ought to form an interesting overall picture of boot-up times on managed switches.

[UPDATE: Further to those who think I am asking about boot-up time because I am silly enough to think that has anything to do with the actual operational performance, I have updated the above, to make it more clear that I'm interested in understanding the norms of this hardware type, not in forming an overall impression on switch performance based on one edge-case of boot time. Thanks for your time.]

[UPDATE2: I'm going to add my own answer for the managed SRW switch that we bought yesterday, a Cisco (former-linksys) model ... Is there anything wrong with not accepting AN ANSWER On this? I'd like to keep this question open to collect data points which might be useful to others, as well as to myself. In general, the longest time is 5 minutes, and the shortest are 1-2 minutes, with a nifty exception for the one HP ProCurve mentioned, which is super fast. ].

switch gigabit-ethernet

4 Answers

  1. I can't imagine a reason why you would be rebooting switches often enough in any environment to even worry about this. Any reboot of a switch should be done in a maintenance window and then a few minutes isn't going to be a big deal.

    I'm not sure how you think that booting time reflects the switch performance. Switches, like most embedded devices, will have an underpowered CPU of some sort which is responsible for the booting process and maybe a few functions such as running the cli or web interface. But almost all of the networking functions are going to be handled by purpose built ASICs and won't involve the CPU at all.

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  2. SRW2048 from a cold start running 1.2.1, 97 seconds

    tsavo:~ mcd$ date
Mon Apr 12 14:04:48 EDT 2010
tsavo:~ mcd$ ping 192.168.24.70
PING 192.168.24.70 (192.168.24.70): 56 data bytes
Request timeout for icmp_seq 0
Request timeout for icmp_seq 1
Request timeout for icmp_seq 2

... snipped ...

Request timeout for icmp_seq 85
64 bytes from 192.168.24.70: icmp_seq=86 ttl=64 time=45.284 ms
^C

tsavo:~ mcd$ date
Mon Apr 12 14:06:25 EDT 2010
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  3. Best Answer

    Ok here's another data point for you from a PowerConnect 5324. Which is a few generations behind the models you're looking at. So take it for what it's worth.

    So the ping command below was sending 1 ping per second to you can see from the output below that it took 108 seconds from the point where it went down from the reload command to the point that it started replying again.

    PowerConnect 5324 reboot 108 seconds

    date && ping 192.168.0.2 && date
Thu Apr 15 00:06:45 EDT 2010
PING 192.168.0.2 (192.168.0.2) 56(84) bytes of data.
64 bytes from 192.168.0.2: icmp_seq=1 ttl=64 time=2.53 ms
64 bytes from 192.168.0.2: icmp_seq=2 ttl=64 time=2.54 ms
64 bytes from 192.168.0.2: icmp_seq=3 ttl=64 time=2.55 ms
64 bytes from 192.168.0.2: icmp_seq=4 ttl=64 time=2.60 ms
64 bytes from 192.168.0.2: icmp_seq=5 ttl=64 time=2.55 ms
64 bytes from 192.168.0.2: icmp_seq=6 ttl=64 time=2.76 ms
64 bytes from 192.168.0.2: icmp_seq=7 ttl=64 time=2.50 ms
64 bytes from 192.168.0.2: icmp_seq=8 ttl=64 time=2.63 ms
64 bytes from 192.168.0.2: icmp_seq=9 ttl=64 time=3.51 ms
....
64 bytes from 192.168.0.2: icmp_seq=117 ttl=64 time=2026 ms
64 bytes from 192.168.0.2: icmp_seq=118 ttl=64 time=1028 ms
64 bytes from 192.168.0.2: icmp_seq=119 ttl=64 time=30.1 ms
64 bytes from 192.168.0.2: icmp_seq=120 ttl=64 time=3.80 ms
^C
--- 192.168.0.2 ping statistics ---
120 packets transmitted, 13 received, +45 errors, 89% packet loss, time 119202ms
rtt min/avg/max/mdev = 2.502/239.520/2026.970/583.213 ms, pipe 4
Thu Apr 15 00:08:45 EDT 2010
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  4. I don't have the exact times on hand, but we have both Cisco (3750) and HP switches (2524 & 2510G). The Cisco ones indeed take several minutes to start up. The HP ones take about 30 seconds. The HP ones are 24 port, and it tests each port (does about 4 ports per second), so a 48 port would take slightly longer.

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