If two machines are affected and they don't have an identical setup, then it rather points to a transmission problem than a problem with the computer.

Since it doesn't seem to be a widespread problem, perhaps a 'reception' problem - what's received by your particular modem/router, rather than what's transmitted by the project.

I have seen cases where routers produce a very pretty graphical error page when something goes wrong - which is helpful if you're sitting at a browser and can read it, unhelpful if it's handed to a program like BOINC. BOINC ignores very small files if received in error, which weeds out most text-based error messages, but the graphical ones can be big enough to be mis-intepreted as data.

That might explain why both machines get occasional errors, but it's hard to see that a problem like that would start because of the upgrade to Windows 10 and subsequent reversions. Was that done on your other half's machine too?

Greetings Richard,

No, she upgraded to Window$ 10 and stayed with it. Her PC is one Intel generation below mine: I have an i7-4771 and if I'm not mistaken hers is an i7-3770K.

I know it sounds weird that I say this started after my upgrade to Window$ 10 and then the roll back to Win7, but that's really what happen. Before Window$ 10 hit this PC I never once saw any MD5 errors. I have been checking my error list for years and other than an occasional computation error, there was never an MD5 error.

I looked at my modem's log and found nothing. I have no idea if it even logs errors. All I can find is a text-based log and all I saw in it was what was allowed and what was blocked. I could find nothing mentioning errors. It's a Motorola SURFboard eXtreme DOCSIS 3.0 cable modem. It was about the only one I could find that was on the ISP compatibility list. I got it in March of 2014.

I will see what I can do about the router. I don't know that I have browser access to it or not. Someone here mentioned making a direct connection to the modem with both PCs to see what happens. If this proves to be the router's fault then a new router would be in order. It's a Netgear Super-G WGT624 Wireless router. I got it back in January of 2008. It's almost 8 years old! Ok, yes, it's high time I get with the times and upgrade to the latest technology. ;) BTW, my memory it ain't so good anymore. The reason I can lock down the dates of purchase so closely is because I am a stickler for keeping receipts for technology equipment. They are in the original boxes for easy access. ;)

Hope this helps somewhat. :)

Keep on BOINCing...! :)

[edit] DUH! I just accessed the router! :/ It's the modem I don't have access to that I know of. [/edit]

---

CAPT Siran d'Vel'nahr - L L & P _\\//
Winders 11 OS? "What a piece of junk!" - L. Skywalker
"Logic is the cement of our civilization with which we ascend from chaos using reason as our guide." - T'Plana-hath

The address to your modem or router is manufacturer specific On my Zoom router\modem it is 192.168.0.1.

Herb

There are a number of modems in the Surfboard DOCSIS 3.0 range, but a likely one looks like

http://www.surfboard.com/wp-content/uploads/2014/07/ARRIS_SURFboard_SB6121_User_Guide.pdf

(and I expect they all have similar management screens)

The default address would be http://192.168.100.1, and you can read the rest onscreen or from page 10 (16th page of the PDF) of that user guide.

I know that it seems like the upgrade/rollback might have had something to do with your problems, I really would be looking at a new router. I can not remember what the problem was but I suddenly (a few years back) was having problems with communications. It turned out the router was just old and with newer software/hardware was not working properly. (and I had just changed something but it was not making sense to me that it could be the router). I changed the router and as if by magic, all was working again.

Just my thoughts on your problem at this point considering the age of your router.

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SETI@home classic workunits 4,019
SETI@home classic CPU time 34,348 hours

There are a number of modems in the Surfboard DOCSIS 3.0 range, but a likely one looks like

http://www.surfboard.com/wp-content/uploads/2014/07/ARRIS_SURFboard_SB6121_User_Guide.pdf

(and I expect they all have similar management screens)

The default address would be http://192.168.100.1, and you can read the rest onscreen or from page 10 (16th page of the PDF) of that user guide.

Greetings Richard,

Well, I'll be damned! ;) I had no idea there was access like this to the modem. Why would they not include this in the literature with the modem, I wonder? BTW, you just happened to pick the same model as my modem, SB6121.

I looked at the logs. It is all Greek/Latin to me!

I have learned some more about this network setup. I have one weak link, the router. Everything but the router is 10/100/1000 LAN speed: Modem, 5 port Ethernet switch and 2 PCs. The wireless router is only 10/100. So... an upgrade to a new router will be in order near the end of this month.

I tried connecting the switch and 2 PCs directly into the modem. The modem LAN indicator changed to blue (high speed). The light on my adapter changed to green (high speed). But, the PC could not connect to the Internet. And, I believe I just discovered why. The information for the switch says it requires Cat 5e cable for high speed. But, why would my PC detect high speed...

This is weird. I just connected the switch directly to the modem bypassing the router, again. Her PC said it had Internet access, but she could not access any websites. Mine could not make any connection I assume because I have Cat 5 cable to the switch, hers has a Cat 5e cable to the switch. Could it be because there was no DHCP involved? Nope, the modem has DHCP protocol, maximum of 32 addresses. I'm so confused... O_O

Keep on BOINCing...! :)

---

CAPT Siran d'Vel'nahr - L L & P _\\//
Winders 11 OS? "What a piece of junk!" - L. Skywalker
"Logic is the cement of our civilization with which we ascend from chaos using reason as our guide." - T'Plana-hath

shutdown your computer when you switch routers/modems, they have different DHCP servers, and different addresses.

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http://pc.net/helpcenter/answers/difference_between_router_and_modem

---

- Performance is not a simple linear function of the number of CPUs you throw at the problem. -

http://pc.net/helpcenter/answers/difference_between_router_and_modem

Very true, but I think I'd take issue with their final paragraph:

While the router and modem are usually separate entities, in some cases, the modem and router may be combined into a single device.

That may have been true some years ago, but nowadays I'd swap it round: I haven't seen a 'pure' modem for years - every device I've worked with has been a combination of both functions.

In particular, I'd suggest that the SURFboard SB6121 we're looking at here has the characteristics of a router as well as a modem - and it's a little misleading of Motorola not to make that clear.

The increased availability of routers is a very good thing. Apart from allowing multiple devices to share a single connection - all Siran really needs is a wireless access point, rather than a second router - the address translation provided by a router usually supplies the essentials of a basic firewall, protecting your computers from internet attack. I'm surprised the user guide - and the online reviews - are not more explicit about the IP address management of these devices, but to my eye if you can access the configuration page on 192.168.100.1 (defined as a private, non-routable address by rfc 1918), and at the same time access the internet over the same device, then you're using a router.

Greetings everyone,

@Richard: Thanks for all your very insightful help. To me it is priceless. :D BTW, I priced those access points and they are way more expensive than the routers. I will let the router (see link below) deal with internal IP addresses.

@Everyone: To all that gave suggestions, thank you too. :D

At this point, with one more experiment to do, there is nothing more that can be done until after the 28th. At that time I will be ordering this router and 2 or 3 Cat 5e cables. Once installed, running and configured, I will see what happens. Whether or not this issue gets resolved with the new equipment, I will post about it here.

Once again, thank you all for your help! :)

Keep on BOINCing...! :)

---

CAPT Siran d'Vel'nahr - L L & P _\\//
Winders 11 OS? "What a piece of junk!" - L. Skywalker
"Logic is the cement of our civilization with which we ascend from chaos using reason as our guide." - T'Plana-hath

I'm using a Netgear WN 604 - not the same performance as the one you chose, but fit for my purpose (smart WiFi TV too far away from the wired router in my basement).

I'm using a Netgear WN 604 - not the same performance as the one you chose, but fit for my purpose (smart WiFi TV too far away from the wired router in my basement).

Greetings Richard,

Yeah, I decided that the greater Mbps would do our 6 wireless devices some good. The WN 604 is only slightly faster than what I already have, running up to 108 Mbps. ;) And, our new 40 inch TV is not a smart TV. But then, our BlueRay player has wired connection to the router so a smart TV would not be required. ;)

Keep on BOINCing...! :)

---

CAPT Siran d'Vel'nahr - L L & P _\\//
Winders 11 OS? "What a piece of junk!" - L. Skywalker
"Logic is the cement of our civilization with which we ascend from chaos using reason as our guide." - T'Plana-hath

Greetings,

The final experiment confirmed that the other half's PC could connect to the modem through the switch (router removed) and then access websites. It was running at 1 Gbps LAN speed. My PC could not make a connection to the modem through the switch (router removed) presumably due to the cable from switch to my PC not being Cat 5e. Her cable is Cat 5e to the switch, the cable from modem to switch is Cat 5e. In just over 3 weeks we will see some improvement and hopefully an end to these MD5 errors. Here's crossing fingers X! :)

Keep on BOINCing...! :)

---

CAPT Siran d'Vel'nahr - L L & P _\\//
Winders 11 OS? "What a piece of junk!" - L. Skywalker
"Logic is the cement of our civilization with which we ascend from chaos using reason as our guide." - T'Plana-hath

Greetings,

Later today there will be a moment of truth... after maintenance that is. I have gathered parts and pieces and will be rebuilding (updating) our network system. Once done, we will see if these danged errors disappear. :)

Wish me luck! :)

Keep on BOINCing...! :)

---

CAPT Siran d'Vel'nahr - L L & P _\\//
Winders 11 OS? "What a piece of junk!" - L. Skywalker
"Logic is the cement of our civilization with which we ascend from chaos using reason as our guide." - T'Plana-hath

Greetings,

I have NOT seen the dreaded MD5 download error for 2 days. Perhaps the issue has been resolved.

RESOLUTION:

• New Netgear N750 Wireless Dual Band Gigabit Router
  
• 2 new Cat6 cables
  
• 1 Cat6 cable replaced with original Cat5e cable (more on this below)
  

I discovered that my PC was still running at 100base-T LAN speed. The other PC is running at gigabit speed. I used the utility in Device Manager to change to gigabit speed and lost connection. I pulled out my 50 ft Cat5e cable and ran it from the router to my PC and lo and behold, I'm now running at gigabit speed. Go figure... :\

I googled this and found that someone else had the same problem and went back to his Cat5e cable to resolve his issue.

Both of our motherboards here are ASUS. One works with Cat6 and one does not. Go figure... :\

Any clues? By the way, both Cat6 cables are from the same manufacturer. Different colors though, one purple and one white. ;)

Keep on BOINCing...! :)

---

CAPT Siran d'Vel'nahr - L L & P _\\//
Winders 11 OS? "What a piece of junk!" - L. Skywalker
"Logic is the cement of our civilization with which we ascend from chaos using reason as our guide." - T'Plana-hath

Greetings,

I have NOT seen the dreaded MD5 download error for 2 days. Perhaps the issue has been resolved.

RESOLUTION:

• New Netgear N750 Wireless Dual Band Gigabit Router
  
• 2 new Cat6 cables
  
• 1 Cat6 cable replaced with original Cat5e cable (more on this below)
  

I discovered that my PC was still running at 100base-T LAN speed. The other PC is running at gigabit speed. I used the utility in Device Manager to change to gigabit speed and lost connection. I pulled out my 50 ft Cat5e cable and ran it from the router to my PC and lo and behold, I'm now running at gigabit speed. Go figure... :\

I googled this and found that someone else had the same problem and went back to his Cat5e cable to resolve his issue.

Both of our motherboards here are ASUS. One works with Cat6 and one does not. Go figure... :\

Any clues? By the way, both Cat6 cables are from the same manufacturer. Different colors though, one purple and one white. ;)

Keep on BOINCing...! :)

I had a similar issue, one pc running at 10/100, the other at 10/100/1000, due to a faulty port on a Netgear 5 port Gigabit switch. Change ports, all ok, change back (to test) still all ok, go figure ;-)

P.

---

http://pc.net/helpcenter/answers/difference_between_router_and_modem

Very true, but I think I'd take issue with their final paragraph:

While the router and modem are usually separate entities, in some cases, the modem and router may be combined into a single device.

That may have been true some years ago, but nowadays I'd swap it round: I haven't seen a 'pure' modem for years - every device I've worked with has been a combination of both functions.

In particular, I'd suggest that the SURFboard SB6121 we're looking at here has the characteristics of a router as well as a modem - and it's a little misleading of Motorola not to make that clear.

The increased availability of routers is a very good thing. Apart from allowing multiple devices to share a single connection - all Siran really needs is a wireless access point, rather than a second router - the address translation provided by a router usually supplies the essentials of a basic firewall, protecting your computers from internet attack. I'm surprised the user guide - and the online reviews - are not more explicit about the IP address management of these devices, but to my eye if you can access the configuration page on 192.168.100.1 (defined as a private, non-routable address by rfc 1918), and at the same time access the internet over the same device, then you're using a router.

Ok I have an SB6121, the modem has only one ethernet port on the back, if the modem had more, I'd have to agree on the modem/router, My router is a Netgear 3500 Gigabit router and I run Cat6, some models like the SBG6580 are combined as shown in the pic below.

The SB6121 has almost nothing on the back, as does the SB6141 and the SB6183, I'm looking to get a Black SB6183 to eventually replace My SB6121 with, yeah they do exist. Arris now makes the modems that used to carry the Motorola brand name. Though even the 6183 is about to be passed by, the new modem is the SB6190 with double the speed capability, the SB6190 is a Docsis 3.1 modem, not everyone supports this modem yet.

---

The T1 Trust, PRR T1 Class 4-4-4-4 #5550, 1 of America's First HST's

http://pc.net/helpcenter/answers/difference_between_router_and_modem

Very true, but I think I'd take issue with their final paragraph:

While the router and modem are usually separate entities, in some cases, the modem and router may be combined into a single device.

That may have been true some years ago, but nowadays I'd swap it round: I haven't seen a 'pure' modem for years - every device I've worked with has been a combination of both functions.

In particular, I'd suggest that the SURFboard SB6121 we're looking at here has the characteristics of a router as well as a modem - and it's a little misleading of Motorola not to make that clear.

The increased availability of routers is a very good thing. Apart from allowing multiple devices to share a single connection - all Siran really needs is a wireless access point, rather than a second router - the address translation provided by a router usually supplies the essentials of a basic firewall, protecting your computers from internet attack. I'm surprised the user guide - and the online reviews - are not more explicit about the IP address management of these devices, but to my eye if you can access the configuration page on 192.168.100.1 (defined as a private, non-routable address by rfc 1918), and at the same time access the internet over the same device, then you're using a router.

Greetings Richard,

HOLY CRAP!!! I was just looking into information you posted and what Zoom314 posted and discovered something very odd. (see below)

Like he has, I have a SB6121 SURFboard modem. I also now have a Netgear N750 Wireless Dual Band Gigabit router. I have eliminated our 5 port switch. The modem has, if memory serves, 32 addresses it can assign. I assume that since this is done through a single LAN port on the modem that a switch or switches would be involved between it and the connected devices thus eliminating a router and using the modem as the router. Correct?

Here's the odd thing: I was looking at the Addresses page of the modem in my browser. It shows the HFC MAC Address, etc. One thing I saw was a Known CPE MAC Address (Max 1), CPE meaning Customer Premises Equipment. That is supposed to be the MAC Address of the router, in my case. I assume these are hexadecimal numbers. The last number does not match the number on the box the router came in or the router. The other 5 numbers do match the number on the box and router. The number on the box and router is C9 while the number displayed by the modem is CA. Why would my modem display a number other than what is on the box and router? Could my router and box be miss labeled?

By the way, 5 days and still no MD5 errors. Woohoo! :)

Keep on BOINCing...! :)

---

CAPT Siran d'Vel'nahr - L L & P _\\//
Winders 11 OS? "What a piece of junk!" - L. Skywalker
"Logic is the cement of our civilization with which we ascend from chaos using reason as our guide." - T'Plana-hath

I can see we could use a primer on ethernet TCP/IP address spaces and routing. Maybe when my brain gets back from Edinburgh (see other thread).

Greetings,

Ok! Where did I get the impression that the SB6121 modem had a built-in router? It stands to reason that if it had, there would be more than one LAN port on the back of it. DUH! :|

Keep on BOINCing...! :)

---

CAPT Siran d'Vel'nahr - L L & P _\\//
Winders 11 OS? "What a piece of junk!" - L. Skywalker
"Logic is the cement of our civilization with which we ascend from chaos using reason as our guide." - T'Plana-hath

Greetings,

Ok! Where did I get the impression that the SB6121 modem had a built-in router? It stands to reason that if it had, there would be more than one LAN port on the back of it. DUH! :|

Keep on BOINCing...! :)

Nobody is perfect, so no worries, I've been using computers for ages, since 1980, the internet was something I had to configure by Myself in 1992, since before this, online was by modem over phone lines(dialup) to what was called a BBS, now known as a Forum.

I even have 2 pieces of Cat6 ethernet cable connected to each other by a shielded ethernet coupler, works great at 1 Gigabit.

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The T1 Trust, PRR T1 Class 4-4-4-4 #5550, 1 of America's First HST's