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Motorola SB5100 / SB5101

details: SURFboard 5100 DOCSIS 2.0 cable modem with Ethernet and USB connectivity
hardware type: Cable Modem
date added: 2006-01-23
updated: 2014-09-22
The Motorola SURFboard 5100 / 5101 is a DOCSIS 1.1 and 2.0 Certified cable modem capable of providing up to 38Mbps downstream, and 30 Mbps upstream data rate.

The modem features both USB and Ethernet connectivity, as well as web based diagnistics for quick troubleshooting.

The SURFboard 5100 incorporates DOCSIS 2.0 Advanced Time Division Multiple Access (A-TDMA) and Synchronous Code Division Multiple Access (S-CDMA) technologies to provide up to three times greater upstream capacity than DOCSIS 1.0/1.1 systems.

The SURFboard SB5100 also features a top-mounted stand-by button that quickly isolates the USB and Ethernet connection to the PC without disconnecting the cable modem from the RF network.

» Forums search for Motorola SB5100 / SB5101
 SB5100 / SB5101 Features
 Availability: discontinued
 Street price: $50
 LAN / WAN Connectivity
 WAN throughput: 38 Mbps
 WAN throughput upstream: 30 Mbps
 WAN ports: 1
 WAN port(s) type: Coax F-connector
 LAN ports: 1
 LAN ports type: 10/100 Base-TX (RJ-45)
 USB port(s): 1
 Cable Modem
 DOCSIS compliance: DOCSIS 1.1
 Cable Diagnostics: yes
 Device Management
 Default IP address:
 Administration: Web-based (LAN)
Remote centralized management
 Firmware upgradeable: yes
 Event log: yes
 Misc hardware info
 Chipset: SB5100: Broadcom BCM3348; SB5101: Broadcom BCM3349
 Power over Ethernet (PoE): no
 Notes: SB5101 contains a different chipset.
 Product page:

Please use the Add Comment function below to review devices you have used (please be descriptive). If you find an error in our database, or have additional information about the product, please
  User Reviews/Comments:
by Brent - 2006-02-16 22:20
Great Modem, no problems with it, purchased one to lower monthly cable bill has paid itself off a long time ago. Only downside in the onboard interface is that it doesn't show you what upload/download speeds in KB that you are negotiated at, but all other information such as signal strength and frequencies are there.

Comcast has pushed updates that worked automatically with no user interaction from my end, didn't even know it happened till I went in and found a newer version of the software was in place, which provided the recent speed upgrade Comcast has doled out, 8mbps/256kbps with the speed tier which this Modem handles nicely.
by Brent - 2006-02-16 22:22
Correction, 8mbps/768kbps speeds with the speed tier, modem handles it nicely.
by Lefty - 2006-02-18 15:33
No problems with my surfboard ever. Running good for almost two years.
by perkins1983 - 2006-03-01 17:47
had problems since i got it download speed are not what they are supposed to be
by Amro - 2006-03-18 00:18
that has nothing to do w/ the modem. that's a service issue.
by Liquibyte - 2006-06-18 18:09
No out of the box options! Does not network well at all with a wireless router (D-Link DI-524)! Makes me wonder why I switched from DSL! I'm tired of jumping through hoops to make a network. I didn't ask my modem to decide for me, and yet they think I need this to exist. Why can I not configure this modem? Hmmm, perhaps they don't like more than one computer online at the same time, sounds like an EULA to me. Let's test the validity of these things in court. I cry Bullshit!!!
by morbidpete - 2006-06-25 18:13
@ Liquid, What! Yea ok

Anyways. Working Great for me, Internal Page helped greatly in prving my theorory of bad Db when trouble shooting my modem with a tech
by rawkus101 - 2006-07-27 13:26
I had mine for three years now never had any trouble over all a very good modem even tho im due for major upgrading on both sides...
by anonymous - 2006-08-01 01:38
that's odd 'cause I have the same wireless router (rev c) and modem and it networks just fine
by anonymous - 2006-09-25 20:19
works fine with my linksys router
by skippydunbar - 2006-09-30 09:44
Works great with my 8 Mb service from Comcast. But that is probably because I rearly get the full 8Mb of bandwidth I'm paying for. If I'm up in the middle of the night it is blindingly fast. Durring the day it's just OK... But thats more Comcast's fault then Motorola... And yes Comcast does not like it when they find out you have a router and multipal computers connected.. But I just lie to them and say "No I dont have a router!", and "No I dont have more then one computer!", and "No you cant come to my house and check"... When they do show up, my big german sheppard ask's them to leave...

I think I was better off with DSL... It's not as fast as cable but it is consistent... I got what I was paying for...
by Psycho - 2007-02-25 16:55
skippydunbar, thats not true they dont support routers, but they dont NOT allow you to have them. they only support their own routers VIA home networking customers :)
otherwise just residential customers can do what they please, however if the modem is online and active but its your router thats having trouble then thats your problem, or your router manufactures problem :D

anywho yea the motorola modems are GGRREEEAT! they came out with two newer models which are wireless, making them a gateway



however the sbv5220 is actually a voice modem an Emta. but still pretty cool.

oh and liquid is an idiot.
by PCline - 2007-03-21 13:23
motorola sb5100 is like the da next best thing to the best thing out there....i`ve never had any other modem for 3 i`d say this is the best...confusing until u get one and experience the "troubleshooting free experience".
btw if u had problems with this modem.....its a knock off...the originals are simply outstanding!!!
by Sean9 - 2007-09-07 15:08
I'd give the Motorola SB5100 a 4.5 out of 5 though I entered a "4." After 3 years it's worked flawlessly.
I have the CM connected to a firewall/router, feeding up to three PCs.
The only time it's been off was in power OR ISP outages.

**Does anyone know how to change the cm's IP address?**
by anonymous - 2007-10-06 12:05
I'm looking at getting this to replace my 3-yr old SB5100, which is erratically dropping the signal, requiring a power-off-power-on cycle to work again. I'd gamble that if the SB5101 lasts 3 years, it's worth it.
by jerin8 - 2007-12-05 22:30
Lets just clarify the whole Comcast issue in that I'm a Level 3 techinical support specialist for thier high speed data services. (Internet Protocol Support Services). Comcast dosent care if you have a router. In fact we all have routers. We just dont see why we should provide free technical support, that is technical SUPPORT for Linksys, D link, Belkin or whatever brand your using. They have their own technical support. In addition all I have to do is have you read me the IP address on your computer and I immediatly know that you are using a router or if your not so bright, that you have your modem in standby. We know what IP address, DNS servers, DHCP servers etc. we provide you and much much more. We also know what IP address your router will provide each computer in the home. This part is common knowledge in the LAN world. So please dont waste your time denying it it just takes longer to diagnose your present connectivity problem.
In regards to motorola modems. I love them. They are fast, reliable , stable, and long lasting work horses. Occasionally you get a lemon but by and large they fail much less than any other modem that we distribute or that can be bought by the consumer. In addition there is not a single router that they wont dance with unlike some of the other modems like thomsons or rca\\\'s, zytel, zoom. etc.

Sean9 which IP address are you wanting to change? The internal local IP starting with 192? Or the actual IP of the modem starting with a 71. or 10.? Or is it the IP provided by the modem by your ISP that starts with something like a 68. or 69. or another 2 digit number similar? You cannot change the IP provided by your ISP unless they provide static IP\'s than, maybe.
by anonymous - 2008-02-04 17:12
What is the internet type?
by anonymous - 2008-03-14 15:44
I have an SB5101 and upgraded to Comcast Blast a couple of days ago. Comcast keeps pushing me the file for a 5100 which results in an error

SW upgrade Failed after download - Incompatible SW file
SW Download INIT - Via Config file

I spend 3 hours on the phone with various support folk last night to try to get the right file pushed,, with no luck. They show my equipment as SB5101 but nobody had a clue about how to get me the right file.

Any ideas? Thanks.
by anonymous - 2008-06-15 16:02
I initially thought I had problems with the modem, then the router, however it eventually (after 6 weeks of daily being knocked off every few hours) was discovered that the coax had been eaten through.

CableOne was the best about it once they knew what it was, new conduit to the house including digging under the road and never a charge for any of it even service calls. They even gave me some free internet time (3 months). I am not used to cable companies being responsive, courteous, and making an investment in the customer.

So my 2 year old sb 5100 I'd rate at 5 though I am having a situation right now where if I don't use the internet for a period of time it seems to lose the connection. However that's probably a problem with the pc or the router, not the modem (no settings for any of that).

Thank you SG for providing the ip config address too, looked all over for that.
by rebelbrowser - 2008-06-27 22:28
jerin8: "The internal local IP starting with 192? Or the actual IP of the modem starting with a 71. or 10.?"

pray-tell why does my modem seem to all of a sudden have this 71 ?
how can I access my pc when directly connected to it now.
I did it before by using my ip address, now I have two ips to get through.
noone I spoke to thus far has a clue. And since you admit you work for CC I figured I would spare myself the embarrassment of asking my boss whats up with dat.
troubleshooting Windows IIS through a router led me to learn my modem is the culp. hmmmm 2 ips huh.
either I get it back to the way it was /brideged or what ever/ or learn how you expect me to access my server that way.
And teach the others at tech support too will ya !
by j - 2008-07-15 00:11
The Motorola SURFBoard broadband "modem" is well-loved by most tech/help desk/support personnel & their cable company employers.
Perhaps not so much by those companies' customers who are often left with no way to do much beyond surf the internet/WWW.
Even using simple state-of-the-art bit torrent software can be almost impossible, because the Motorola SURFBoard "modem," and the cable companies, in general don't allow/provide anyway to 'bridge' the the two sets of IP addresses that these setups typically require.
Although the SB 5100/5101s are by all accounts reliable, the software is not 'user accessible' or 'user friendly' at all.
And although I've never seen a EULA/TOS statement that prohibits the customers from trying to "help" themselves, apparently the customer is expected to tolerate the situations that others have mentioned here w/out making any efforts to resolve or aid the situation, especially the inability of either the cable companies, their tech support, or their customers to adjust or tweak the hardware.
Locally, the cable company had a great reputation for dependable lightning-fast service, even if the support was a little 'slow.'
After one software "upgrade," the speed of the service actually went down.
Quite some time later, (approx. 8 months) the cable company finally decided to raise the max speed to compensate for the lower speeds produced by the "upgrade." (Some online 'speedometers' now show 1.5 MB.)
The following posters on have the appearances of the problems ISPs produce for their customers by using the Motorola SB 5100/5101 SURFBoards.

anonymous [24.7.x.x] - 2007.10.06 12:05
(probably caused by cabling/connection issues— see anonymous [24.117.x.x] - 2008.06.15 16:02)
anonymous [76.103.x.x] - 2008.03.14 15:44 (another software problem)
anonymous [24.117.x.x] - 2008.06.15 16:02
jerin8 - 2007.12.05 22:30
(makes the point—3 different IP addresses, any of which could be causing Sean9's problem.)
rebelbrowser - 2008.06.27 22:28

The "Default IP address" of '' is standard for all SB 5100/5101s, which is somewhat surprising given that "ipconfig" gives the following results on my machine.

"IP Address. . . . . . . . .
"Subnet Mask . . . . . . . .
"Default Gateway . . . . . ."

After using a Motorola SB 5100 for about 3 years now, I can say this about them.

All in all, yes the Motorola SB 5100/5101 SURFBoard cable 'modem' is reliable.
But the way its used by cable companies, the pathetic software, and the total lack of options or customer choices indicate that its just as useful & utilitarian as the poles that hold the cable coax up in the air.
And just about as desirable next to your computer, too.
by anonymous - 2008-08-01 17:07
whats the difference between the 5100, 5101, and 5102??

by anonymous - 2008-09-29 05:21
the modem won't connect to my computer at all - it is a pice of ...
by yep - 2008-10-09 06:50
Well, no matter what anyone says, the 5101 beats the pants off the hot runnng, connection losing Ambit modem they put on the end of my cable. To change your IP address, if it's not static, is to release the IP address, unscrew the cable from the cable modem, turn off your pc, wait a few hours and reconnect and hook your cable back up. This is if you live in a big city. If you live in a small town, you may have to wait a day so someone else will connect and get your old address first. Oh yeah, renew your IP address after you get running again. Works for me everytime. Be banned no more!!!
by jeon sah - 2008-12-28 13:14
I've had this modem for two years now, using shaw internet service provider, and I was quite happy, as I used it for gaming, and my latency was quite nice to players close to me.

Then I reformatted my PC, and I ended up re-downloading all the default drivers of my PC that were needed, and my ping shot straight up, upto 300 ping, which is QUITE bad.

Specifically, in the game I play, the closer you are to the player, the less your ping is to them, and it's rather easy to kill them. However, with this router, I alt-tabbed to watch some youtube videos, and when I alt-tabbed back in, pings were increased by almost 40%, which is quite astonishing.

If anyone can provide a fix for the following, as it would be great, may be that I've reached my bandwidth quota, so my isp is not letting my internet boost itself to the full of its speed.
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