SG300 L3 Performance

[Kristofvdb]

Hi,

We have a network with over 300 devices . We have one primary switch (SG300-52 L2) with 10 secondary switches (SG300-28 L2) to handle all the traffic.

Alle devices are operating in the same subnet (10.10.0.0/16), and in the same VLAN.

Because we have quiet a lot of video-traffic on the network we want to split the network in 10 different VLAN's and change the primary switch from L2 to L3.

Each VLAN will handle one subnet (10.10.x.0/24) with 15 devices (video).

The routing between the VLAN's will be done by inter-VLAN-routing in the SG300-52

Is a SG300-52 switch in L3-mode able to route this amount of devices in a decent way ? Or do we need a more performant switch/router ?

Best regards,

K.

[Tom Watts]

Hi Kristof, the only thing I am personally concerned about with layer 3 performance on these switches would be the number of forwarding requests. This is a pretty robust switch but there is a time where it may not be able to forward all requests. In this condition you will receive SFFT Table Overflow error. Such as this example.

2147480831   2012-Jul-06 13:14:45 Warning   %IPFFT-W-SFFTREDYELLOW: IP SFFT Table Overflow, aggregated (1)

2147480831   2012-Jul-06 13:14:45 Warning   %IPFFT-W-SFFTREDYELLOW: IP SFFT Table Overflow

The 1.3.0.62 firmware did enchance the layer 3 capability of the switch especially with the addition of the DHCP server options. On the older releases such as 1.1.2.0 and 1.2.7.76 it would be the forward capacity would be around 100 IP hosts for the switch at a given time.

So the unfortunate answer is, try and find out. The small business products are generally designed for 'small business' which is loosely defined as 100 host or smaller networks with these switch models able to work well as an edge device to larger enterprise deployments.

-Tom
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[Kristofvdb]

Hi Tom,

What do you mean with forward capacity ?

Correct Numbers : I have 1 L3-switch, with 15 ports linked to 15 VLAN's (untagged). These 15 ports are linked to 15 sub-switches with each 20-25 videodevices .

Most traffic will be routed from 1 vlan to the "server"-vlan.

The L3-switch is now on L2, and on firmware 1.1.1.8 and sometimes begins to overflow from traffic (whole network is messed up and only a reboot of the switch bring things back to normal) I just there is a remark in one of the posts in this forum which indicates there is a bug in FW1.1.1.8. First thing we will do is upgrade to the latest FW..but afterwards we want to segment in those VLAN's to have a better control over the network traffic.

K

[Ivor Diedricks]

Kristof,

The forwarding for Layer 3 traffic is performed in silicon (not software) so the performance is wirespeed. You can't get faster than wirespeed. As of the latest releases of firmware, this switch supports up to 128 IPv4 interfaces (you only need 10) and up to 512 IPv4 hosts which again is way beyond what you need. I see no reason why this this cannot work for your environment. You should see a big improvement in network performance since you will have smaller broadcast domains and the inter-VLAN routing being done in hardware. Control plane traffic is done in software, for things like DHCP Relay signaling, IGMP Querier functions, etc), but those are all much lower bandwidth - the data plane is hardware forwarding.

Ivor

[Kristofvdb]

Hi Ivor,

Thanks for the quick reply !

To which model should we best upscale if we are using more than 512 IP-addresses ? (We like to stay in the SG300-range of devices - our core business is not networking )

Edit : I see you are referring to 512 static routes... which we will never have in ths network.

K