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I got an email from Comcast a couple of days ago telling me that Internet speeds in my area are going to be increasing and my current modem (Arris TM722G) will be unable to handle them so I need to get a new modem. I replied to the email to order a new modem which is supposed to arrive today or tomorrow. I found out yesterday that I will be receiving a Cisco DPC3941T which is a combination modem/router. However, I really don’t need the router function since I have been happily using an Apple Time Capsule (and AirPorts before that) with no problems for many years. For the past day or so, I have been scouring both the Comcast and Apple discussion boards trying to figure out the best way to handle the situation with this new modem. Many people say, “Put the modem in bridge mode and continue using the Time Capsule. Just be sure to connect to LAN 1 on the modem because the other ports are disabled.” Unfortunately, the directions for putting a router in bridge mode are somewhat inconsistent (e.g., you need to call Comcast or you don’t). Others say, “Putting the router in bridge setting degrades Internet speeds.” Others provide (what seem to me) convoluted directions for putting the Time Capsule in bridge mode and using the Cisco’s WiFi. Another problem is that many of the things I have found are quite dated - I assume information from 2013 or 2104 may not be relevant today.
It seems to me (an admitted old codger who remembers when this stuff used to be simpler) that there should be a straightforward way to take advantage of the alleged faster speeds that this new modem is supposed to provide without having to reconfigure my entire home network that has been working with virtually no problems for nearly 15 years, running the risk of slower (rather than faster) speeds, or losing the automatic backup provided by the Time Capsule. Any help would be much appreciated, particularly from someone who has had - and solved - this problem.
FYI - I get voice service from Comcast so I need the telephony features in this modem, as well. That part does not seem to be an issue.
Thnaks so much!
Solved! Go to Solution.
Update: Not easy, but it worked eventually. Things were a bit persnickety getting my Cisco device activated, and it wanted me to set up a wireless network on the modem/router. Eventually I got it recognized and was able to follow the instructions to turn on bridge mode. Unfortunately, after I connected my Time Capsule it would not connect to the Internet - no DNS servers and a "double NAT" error message from the TC. I tried resetting the modem as suggested by the TC then, when that didn't work, the TC. When neither of those worked, I did a soft reset of the TC and reset the wireless network on that device. A restart of the TC gave me the same errors. Finally, I did another restart of the Cisco and now things seem to be perking along okay. Total time about 90 minutes. Frustration level about a 4 on a 10 point scale. Because there were so many steps, I can't isolate exactly which one(s) actually solved the problem. I suspect that if I had done things in a slightly different order I would not have had the problems I had.
Speed test before: Comcast: 88.39 up/12.08 down; DSLReports: 88 up/ 12.32 down.
Speed test after: Comcast: 87.96 up/11.71 down; DSLReports 90 up/12.36 down.
No degradation - happy to see that.
Thanks so much, EG, for pointing me in the right directions. Without your help I suspect this would have taken 90 hours rather than 90 minutes.