Do routers remember devices?

Cozarkian

Golden Member
Feb 2, 2012
1,352
95
91
This is just a educational question to satisfy my own curiosity. With almost every dsl/cable internet service I've had, there comes a time when I periodically have to reboot my router. The time period has varied based on the ISP and where I was living.

With my new ISP, however, I have a different variation. My laptop and desktop can usually connect 100% of the time. However, other devices, including a backup laptop, iPad, PS4 and dvd player, will only connect until I attempt to use another device (excluding the laptop/desktop).

For example, the iPad will usually connect daily with no problems, until one day I decide to stream Netflix through the DVD player. I'll have to cycle the router before the DVD player will connect. However, the laptop, desktop, and iPad will still be able to connect without the need for a reset. After I power cylcle, the DVD, laptop and desktop will work fine, but the iPad won't connect without another cycle.

What seems to be happening is that the router is somehow remembering the devices I use most frequently, but can only store 3 devices at one time. Thus, any time I try to add a device, I have to cycle it to dump the 3rd device from memory so another can connect.

Is this a possible behavior, or am I just a victim of coincidence?
 

john3850

Golden Member
Oct 19, 2002
1,436
21
81
The use of a DHCP Reservations List seems to help me avoid those connection problems.
 
Feb 25, 2011
16,800
1,474
126
This is just a educational question to satisfy my own curiosity. With almost every dsl/cable internet service I've had, there comes a time when I periodically have to reboot my router. The time period has varied based on the ISP and where I was living.

With my new ISP, however, I have a different variation. My laptop and desktop can usually connect 100% of the time. However, other devices, including a backup laptop, iPad, PS4 and dvd player, will only connect until I attempt to use another device (excluding the laptop/desktop).

For example, the iPad will usually connect daily with no problems, until one day I decide to stream Netflix through the DVD player. I'll have to cycle the router before the DVD player will connect. However, the laptop, desktop, and iPad will still be able to connect without the need for a reset. After I power cylcle, the DVD, laptop and desktop will work fine, but the iPad won't connect without another cycle.

What seems to be happening is that the router is somehow remembering the devices I use most frequently, but can only store 3 devices at one time. Thus, any time I try to add a device, I have to cycle it to dump the 3rd device from memory so another can connect.

Is this a possible behavior, or am I just a victim of coincidence?

It's possible, if your DHCP pool were configured with a very short expiration date a very small pool limit.

But it's probably just a crappy router.
 

VirtualLarry

No Lifer
Aug 25, 2001
56,389
10,072
126
Do you have administrative control over the router? If so, check the DHCP pool size, and increase as necessary, or set up static mappings for your devices.

The router may also just need a firmware upgrade.
 

Cozarkian

Golden Member
Feb 2, 2012
1,352
95
91
Do you have administrative control over the router?

While that's a problem I may remedy in the near future, currently I'm using the ISP-provided router, which was installed by the tech at the same time they ran the cables, and I wasn't given the login credentials.
 
Feb 25, 2011
16,800
1,474
126
While that's a problem I may remedy in the near future, currently I'm using the ISP-provided router, which was installed by the tech at the same time they ran the cables, and I wasn't given the login credentials.
Is the router physically in your house? Congratulations, you have administrative rights.

They're probably still set to default. Just find the manual online; it'll have them in there.
 

Dahak

Diamond Member
Mar 2, 2000
3,752
25
91
While that's a problem I may remedy in the near future, currently I'm using the ISP-provided router, which was installed by the tech at the same time they ran the cables, and I wasn't given the login credentials.

You can usually google your isp's name and router model and probably find the default login and password
 

riahc3

Senior member
Apr 4, 2014
640
0
0
I don't think its your routing table.....can you control the DHCP client lease time?
 

grendel19

Member
May 3, 2012
134
0
76
Seriously, if this turns out the be a DHCP pool and lease issue, you have to wonder at the tech that set this up. WTH are they doing... But I wouldn't put it past them. I've had issues with Comcast Business where they kept insisting it was our equipment. But eventually, it turned out they dup'ed our public IP on their network. Again, WTH?
 
Last edited:

riahc3

Senior member
Apr 4, 2014
640
0
0
Seriously, if this turns out the be a DHCP pool and lease issue, you have to wonder at the tech that set this up. WTH are they doing... But I wouldn't put it past them. I've had issues with Comcast Business where they kept insisting it was our equipment. But eventually, it turned out they dup'ed our public IP on their network. Again, WTH?
Well, you gotta understand that some of these techs are just install and bye.........and they do that for 8 hours. They aren't gonna waste time configuring each and every router because it consumes time (time=money) and each and every config is different.
 

grendel19

Member
May 3, 2012
134
0
76
Well, you gotta understand that some of these techs are just install and bye.........and they do that for 8 hours. They aren't gonna waste time configuring each and every router because it consumes time (time=money) and each and every config is different.
Not at all, I hear ya. I've worked with ISP level techs (not NOC, but onsite techs) that didn't know what they were doing. I've had one that didn't know how to change his laptop IP to a static on Win7. And I've had to troubleshoot their managed router.

Anyway, sorry to derail the thread. But sounds like most people here are pointing you to the right place to check first.