Re: Gateway server experiencing degraded performance

[Andy Ruhl <acruhl%gmail.com@localhost>]

On Sun, May 15, 2022 at 7:52 AM Andrew K Adams <akadams%psc.edu@localhost> wrote:
>
> Hi, I’ve noticed a problem with my NetBSD server that I really could
> use some help with.  The server is acting as my home router (gateway)
> in ‘pass-through’ mode with Comcast Xfinity as the service provider.
> The only functions/services enabled on the server are: ip-forwarding,
> dhcp-client, and NTP.   And on the internal-facing lan: NAT, DHCP, and
> SSH.  The internal network supports 5+ wired hosts & 10+ wireless
> devices.  I currently have the 1Gig option with Comcast and when
> things are operating as expected, I see from an internal (wired) host
> 750mbs of throughput according to Comcast’s Xfinity speed test
> website.  The problem is that performance doesn’t last.  In anywhere
> from 3 weeks to 24 hours, my network performance (again, using the
> same wired host measured by Xfinity’s speed test) will drop to ~20mbs.
> And the change is clearly observable in all networking applications,
> e.g., Netflix.  I’m querying here, though, because the fix I’ve found
> is to reboot the server.  Upon reboot, I immediately go back to
> 750mbs.  Hence, I’d like to figure out how to troubleshoot what on my
> server is (eventually) degrading my network performance.
>
> The server is relatively new; I built it using an ASUS Mini ITX with
> two onboard GigE ethernet ports.  Here’s some relevant dmesg output:
>
> [     1.000000] NetBSD 9.1 (GENERIC) #0: Sun Oct 18 19:24:30 UTC 2020
> [     1.000000]
> mkrepro%mkrepro.NetBSD.org@localhost:/usr/src/sys/arch/i386/compile/GENERIC
> [     1.000000] total memory = 3457 MB
> [     1.000000] avail memory = 3380 MB
>
> [     1.025286] wm0 at pci0 dev 25 function 0: I217 LM Ethernet
> Connection (rev. 0x05)
> [     1.025286] wm0: interrupting at msi2 vec 0
> [     1.025286] wm0: PCI-Express bus
> [     1.025286] wm0: 2048 words FLASH, version 0.13.4
> [     1.025286] wm0: 0x6a4480<FLASH,IOH_VALID,PCIE,ASF_FIRM,AMT,WOL,EEE>
>
> [     1.025286] re0 at pci3 dev 0 function 0: RealTek 8168/8111 PCIe
> Gigabit Ethernet (rev. 0x0c)
> [     1.025286] re0: interrupting at msix4 vec 0
> [     1.025286] re0: using 256 tx descriptors
>
>
> And from ifconfig (note, I’ve removed my IP & MAC address from the output):
>
> iquitos# ifconfig -a
> wm0: flags=0x8843<UP,BROADCAST,RUNNING,SIMPLEX,MULTICAST> mtu 1500
>         capabilities=7ff80<TSO4,IP4CSUM_Rx,IP4CSUM_Tx,TCP4CSUM_Rx>
>         capabilities=7ff80<TCP4CSUM_Tx,UDP4CSUM_Rx,UDP4CSUM_Tx,TCP6CSUM_Rx>
>         capabilities=7ff80<TCP6CSUM_Tx,UDP6CSUM_Rx,UDP6CSUM_Tx,TSO6>
>         enabled=0
>         ec_capabilities=17<VLAN_MTU,VLAN_HWTAGGING,JUMBO_MTU,EEE>
>         ec_enabled=2<VLAN_HWTAGGING>
>         media: Ethernet autoselect (1000baseT
> full-duplex,flowcontrol,rxpause,txpause)
>         status: active
>         inet X.X.X.X/20 broadcast 255.255.255.255 flags 0x0
>         Inet6 X%wm0/64 flags 0x0 scopeid 0x1
> re0: flags=0x8843<UP,BROADCAST,RUNNING,SIMPLEX,MULTICAST> mtu 1500
>         capabilities=3f80<TSO4,IP4CSUM_Rx,IP4CSUM_Tx,TCP4CSUM_Rx,TCP4CSUM_Tx>
>         capabilities=3f80<UDP4CSUM_Rx,UDP4CSUM_Tx>
>         enabled=0
>         ec_capabilities=3<VLAN_MTU,VLAN_HWTAGGING>
>         ec_enabled=0
>         media: Ethernet autoselect (1000baseT full-duplex)
>         status: active
>         inet 10.19.34.1/24 broadcast 10.19.34.255 flags 0x0
>         inet6 fe80::728b:cdff:febc:831b%re0/64 flags 0x0 scopeid 0x2
> lo0: flags=0x8049<UP,LOOPBACK,RUNNING,MULTICAST> mtu 33176
>         inet 127.0.0.1/8 flags 0x0
>         inet6 ::1/128 flags 0x20<NODAD>
>         inet6 fe80::1%lo0/64 flags 0x0 scopeid 0x3
>
>
> I’m not sure what other information would be useful, just let me know,
> and thank you in advance for help you can give me!

Just a question, not a requirement, but have you looked at Wireshark
traces comparing good performance vs. bad performance?

It's just another way to find possibly find a problem. I'm sure
someone else will have better ideas.

Andy