I have two power routers deployed behind an imagestream router as my headend. I upgraded both of the power routers from 3.11 in once case and 3.17 in the other case to 5.17. The router upgraded from 3.11 is working flawlessly. No issues after the upgrade. The router upgraded from 3.17 is showing extremely high latency. Pinging directly from the router terminal I am seeing latency in the order or 20-90 ms when I ping to a device on that local subnet. The two routers share an interface on one subnet and pinging to a device on that subnet from 1 sees latency of 0 ms while from the other I'm seeing 80-100 ms. Traffic forwarded across the second router is showing latency of 600-800 ms or more and is not getting through at all sometimes. Both routers are attached to the same switching fabric and VLANs are in heavy use. I'm showing resource usage on both of 1-4% CPU and about 10% memory out of a gigabyte available.
What I've tried thus far:
1) pinning the interfaces at 1 Gig. They were auto sensing to 100 mb. This seemed to help a little. latency decreased to 40-50 ms on local devices.
2) I've removed all unnecessary packages (hotspot, routing, etc). This didn't help at all.
One interesting phenomenon. When I ping the border router the ping latency seems to cycle going from 100ms to 80, to 60, to 40, to 20 and then back to 100ms. That seemed fairly consistent. Pinging from the other router to the border gateway (different interface) gives me 0ms consistently.
any suggestions? I'm stumped on this one. One other item to note, the box that is working is a dual core processor, the other is a single core. But, since CPU usage is hovering below 5% I don't think that is the issue.
While I cannot offer any suggestions for actually fixing the problem you are having with one of your PowerRouter 732s, I can share a similar experience that indicates this is a somewhat strange problem with certain versions of these boxes. I have been involved in managing a large network that uses about 25 PowerRouter 732s. At one point, we noticed that three of these units reported only a single core, even though they were all supposed to be dual core processors. These were the first three units deployed in this network in about the late 2008 timeframe. We could find no way to force them to operate as dual core systems. It is also worth noting that these three single-core units showed about twice the CPU loading as the other dual-core units, which seemed to be further evidence that they really were operating as single-core machines.
At one point, we upgraded the firmware on all of these PowerRouter 732s from 3.19 to 4.17. Everything went fine, except for the three units that operated with only a single core. These units took the firmware upgrade, but then behaved very strangely with high latency, just as you reported in your posting. They were unusable in this network running the newer firmware, and we wound up replacing them. I did a moderate amount of fooling around with these units to determine the cause, and even swapped processors between a "good" unit with both cores working, and one of the "single-core" units. The surprise was that the box that was a single core unit, remained a single core unit. Similarly, the processor chip from the "bad" unit worked fine as a dual-core processor in the "good" unit. In other words, the problem seems to be with the motherboard, not the processor chip.
I talked to Link Technologies about this problem, but they were unable to offer any explanations. They indicated they had never encountered a problem like this with a PowerRouter 732. My guess is that there were some hardware problems with earlier versions of the NA-820 models (a.k.a., PowerRouter 732s). We've never encountered the problem with more recent PowerRouter 732s or other NA-820s running RouterOS. It is also worth noting that downgrading one of these "bad" single-core units to RouterOS version 3.xx made them useable again, though only as single-core machines. The other item of interest is that I used these "bad" units for initial testing of newer versions of firmware, and tried them with several earlier versions of 5.xx. While the upgrades were successful, and these units appeared to behave normally, as soon as they started to carry even a little bit of network traffic, the latency problems and other difficulties would start, just a noted in the original post.
Since the problem unit you have was at 3.17, it sounds like it may have been purchased in the same timeframe as the three bad units we had in our network, which were initially shipped with 3.17. This is further evidence of a problem with PowerRouter 732s from this period in time.