Catalyst 3850 Throughput issues

jrmsdepieri · ‎01-30-2022

Hi Cisco Community,

I am a NOOB at this stuff, but I have an IT guy who is helping me (a little in the background), but we are both stumped....

MY ISP is Shaw, and I have the XBR7 modem (latest) on their 1GB package. When I run a speed test with my laptop connected directly to the back of the Shaw modem my throughput is anywhere from 800 Mb - 1.3 GB. Which is what I should be seeing for the package I'm on.

I have a Cisco 3850 - 48 port Switch. When i connect that to the Shaw modem in the CISCO interface I am seeing a 1GB connection. Mostly everything is set to default settings as we reset it after install.

When I plug the laptop into any port. Its shows a 1Gb connection on the interface.

I run the same speed test, and my d/l speed is about a 1/3 around 180Mb - 300Mb.

Upload speed is bang on with ISP package at about 100Mb on the speedtest. Both on Switch and when directly connected to the Shaw Modem so there is no issue at least for now on the Upload. Maybe if I had a higher package i would be having the same issue (don't know).

Best we can determine is something is limiting the download throughput between the Shaw modem and the Cisco switch.

Any assistance here would be great in pointing us to things for us to look at? Anything I should look for on the web interface?

Thanks,

Roger

Flavio Miranda · ‎01-30-2022

Hi

Would be helpful if you run the command "show interface 'interface'" while running the speed test. Let´s see if on the interface output we can see something to justify this different. It alwas can be a problem on the switch but it can also be something else.

If you can share a "show run" as well, would be great.

jrmsdepieri · ‎01-31-2022

Hi Flavio,

I'll try to do this in the next couple of days, and I will post the results...

Thanks for the input!

Roger

jrmsdepieri · ‎02-01-2022

Thank you for the help. I currently only have the two ports used (3 & 4) so below is the show interface while running the speedtest:

ROGERS#show interface GigabitEthernet1/0/3
GigabitEthernet1/0/3 is up, line protocol is up (connected)
Hardware is Gigabit Ethernet, address is 70d3.79fc.3f03 (bia 70d3.79fc.3f03)
MTU 1500 bytes, BW 1000000 Kbit/sec, DLY 10 usec,
reliability 255/255, txload 1/255, rxload 1/255
Encapsulation ARPA, loopback not set
Keepalive set (10 sec)
Full-duplex, 1000Mb/s, media type is 10/100/1000BaseTX
input flow-control is on, output flow-control is unsupported
ARP type: ARPA, ARP Timeout 04:00:00
Last input never, output 00:00:01, output hang never
Last clearing of "show interface" counters never
Input queue: 0/2000/0/0 (size/max/drops/flushes); Total output drops: 0
Queueing strategy: fifo
Output queue: 0/40 (size/max)
5 minute input rate 378000 bits/sec, 49 packets/sec
5 minute output rate 243000 bits/sec, 62 packets/sec
402191 packets input, 364661450 bytes, 0 no buffer
Received 2959 broadcasts (1936 multicasts)
0 runts, 0 giants, 0 throttles
0 input errors, 0 CRC, 0 frame, 0 overrun, 0 ignored
0 watchdog, 1936 multicast, 0 pause input
0 input packets with dribble condition detected
576301 packets output, 579007622 bytes, 0 underruns
0 output errors, 0 collisions, 2 interface resets
0 unknown protocol drops
0 babbles, 0 late collision, 0 deferred
0 lost carrier, 0 no carrier, 0 pause output
0 output buffer failures, 0 output buffers swapped out
ROGERS#show interface GigabitEthernet1/0/4
GigabitEthernet1/0/4 is up, line protocol is up (connected)
Hardware is Gigabit Ethernet, address is 70d3.79fc.3f04 (bia 70d3.79fc.3f04)
MTU 1500 bytes, BW 1000000 Kbit/sec, DLY 10 usec,
reliability 255/255, txload 1/255, rxload 1/255
Encapsulation ARPA, loopback not set
Keepalive set (10 sec)
Full-duplex, 1000Mb/s, media type is 10/100/1000BaseTX
input flow-control is on, output flow-control is unsupported
ARP type: ARPA, ARP Timeout 04:00:00
Last input 00:00:17, output 00:00:00, output hang never
Last clearing of "show interface" counters never
Input queue: 0/2000/0/0 (size/max/drops/flushes); Total output drops: 0
Queueing strategy: fifo
Output queue: 0/40 (size/max)
5 minute input rate 106000 bits/sec, 46 packets/sec
5 minute output rate 362000 bits/sec, 38 packets/sec
6233155 packets input, 1379084394 bytes, 0 no buffer
Received 2003422 broadcasts (1704509 multicasts)
0 runts, 0 giants, 0 throttles
0 input errors, 0 CRC, 0 frame, 0 overrun, 0 ignored
0 watchdog, 1704509 multicast, 0 pause input
0 input packets with dribble condition detected
787439 packets output, 644453291 bytes, 0 underruns
0 output errors, 0 collisions, 2 interface resets
0 unknown protocol drops
0 babbles, 0 late collision, 0 deferred
0 lost carrier, 0 no carrier, 0 pause output
0 output buffer failures, 0 output buffers swapped out

ROGERS#show run
Building configuration...

Current configuration : 9631 bytes
!
! Last configuration change at 20:38:41 UTC Tue Feb 1 2022 by cisco
! NVRAM config last updated at 20:37:14 UTC Tue Feb 1 2022 by Cisco
!
version 16.9
no service pad
service timestamps debug datetime msec
service timestamps log datetime msec
service call-home
platform punt-keepalive disable-kernel-core
!
hostname ROGERS
!
!
vrf definition Mgmt-vrf
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address-family ipv4
exit-address-family
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address-family ipv6
exit-address-family
!
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no aaa new-model
clock timezone UTC -8 0
switch 1 provision ws-c3850-48u
!
!
!
!
call-home
! If contact email address in call-home is configured as sch-smart-licensing@cisco.com
! the email address configured in Cisco Smart License Portal will be used as contact email address to send SCH notifications.
contact-email-addr sch-smart-licensing@cisco.com
profile "CiscoTAC-1"
active
destination transport-method http
no destination transport-method email
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login on-success log
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crypto pki trustpoint SLA-TrustPoint
enrollment pkcs12
revocation-check crl
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crypto pki trustpoint TP-self-signed-2002498183
enrollment selfsigned
subject-name cn=IOS-Self-Signed-Certificate-2002498183
revocation-check none
rsakeypair TP-self-signed-2002498183
!
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crypto pki certificate chain SLA-TrustPoint
certificate ca 01
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43697363 6F312030 1E060355 04031317 43697363 6F204C69 63656E73 696E6720
526F6F74 20434130 82012230 0D06092A 864886F7 0D010101 05000382 010F0030
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418616A9 4093E049 4D10AB75 27E86F73 932E35B5 8862FDAE 0275156F 719BB2F0
D697DF7F 28
quit
crypto pki certificate chain TP-self-signed-2002498183
certificate self-signed 01
30820330 30820218 A0030201 02020101 300D0609 2A864886 F70D0101 05050030
31312F30 2D060355 04031326 494F532D 53656C66 2D536967 6E65642D 43657274
69666963 6174652D 32303032 34393831 3833301E 170D3231 30363238 31363432
34335A17 0D333030 31303130 30303030 305A3031 312F302D 06035504 03132649
4F532D53 656C662D 5369676E 65642D43 65727469 66696361 74652D32 30303234
39383138 33308201 22300D06 092A8648 86F70D01 01010500 0382010F 00308201
0A028201 0100EF03 951037C8 E75578A8 68F8C294 51A04210 181A4656 3A3A757E
2E70D399 9E2AE92C 85C286CA 6855B7B3 C07AB3AF 2B70CF94 363AC200 47FFD3E1
3411CA73 A1CBCB19 56971882 9232D771 B519160E 3429AA8A 16B3CC8B B728E266
F79E87EC E6077A25 339A3EB3 60123546 A15DA4DE 2588E16E FAA898E0 43B62C9E
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0D567CA0 D652EB9B 8C22F65B 7E0FACEB 926B7A96 9CD54195 ADAF6C32 05D28DF7
0AE8CD27 0EE50203 010001A3 53305130 0F060355 1D130101 FF040530 030101FF
301F0603 551D2304 18301680 148FE9B0 E4107B40 E47BBC95 986E51E9 042C3D8C
39301D06 03551D0E 04160414 8FE9B0E4 107B40E4 7BBC9598 6E51E904 2C3D8C39
300D0609 2A864886 F70D0101 05050003 82010100 D27ADDA6 DB9B6B56 65103232
F0346D1B C7D5F952 A773EB82 2739E32F B6B91BF1 6F19B809 F95AF88E A1DAB360
39983DEB CBFA6C24 19893298 59B5446C FD1BD3CD CFC39761 2CE8129D 5CE99BD4
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854A7C01 E396EFD5 197D718C 8A7FD762 2D693DBD 6339D4D9 D5B81F8E 6141120A
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quit
!
license boot level ipbasek9
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diagnostic bootup level minimal
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spanning-tree mode rapid-pvst
spanning-tree extend system-id
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username Cisco privilege 15 password 0 Test123
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redundancy
mode sso
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transceiver type all
monitoring
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class-map match-any system-cpp-police-topology-control
description Topology control
class-map match-any system-cpp-police-sw-forward
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class-map match-any system-cpp-default
description Inter FED, EWLC control, EWLC data
class-map match-any system-cpp-police-sys-data
description Learning cache ovfl, High Rate App, Exception, EGR Exception, NFL SAMPLED DATA, RPF Failed
class-map match-any system-cpp-police-punt-webauth
description Punt Webauth
class-map match-any system-cpp-police-l2lvx-control
description L2 LVX control packets
class-map match-any system-cpp-police-forus
description Forus Address resolution and Forus traffic
class-map match-any system-cpp-police-multicast-end-station
description MCAST END STATION
class-map match-any system-cpp-police-multicast
description Transit Traffic and MCAST Data
class-map match-any system-cpp-police-l2-control
description L2 control
class-map match-any system-cpp-police-dot1x-auth
description DOT1X Auth
class-map match-any system-cpp-police-data
description ICMP redirect, ICMP_GEN and BROADCAST
class-map match-any system-cpp-police-stackwise-virt-control
description Stackwise Virtual
class-map match-any non-client-nrt-class
class-map match-any system-cpp-police-routing-control
description Routing control and Low Latency
class-map match-any system-cpp-police-protocol-snooping
description Protocol snooping
class-map match-any system-cpp-police-dhcp-snooping
description DHCP snooping
class-map match-any system-cpp-police-system-critical
description System Critical and Gold Pkt
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policy-map system-cpp-policy
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interface GigabitEthernet0/0
vrf forwarding Mgmt-vrf
no ip address
shutdown
negotiation auto
!
interface GigabitEthernet1/0/1
!
interface GigabitEthernet1/0/2
!
interface GigabitEthernet1/0/3
spanning-tree portfast disable
!
interface GigabitEthernet1/0/4
spanning-tree portfast disable
!
interface GigabitEthernet1/0/5
!
interface GigabitEthernet1/0/6
!
interface GigabitEthernet1/0/7
!
interface GigabitEthernet1/0/8
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interface GigabitEthernet1/0/9
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interface GigabitEthernet1/0/10
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interface GigabitEthernet1/0/11
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interface GigabitEthernet1/0/12
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interface GigabitEthernet1/0/13
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interface GigabitEthernet1/0/14
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interface GigabitEthernet1/0/15
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interface GigabitEthernet1/0/16
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interface GigabitEthernet1/0/17
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interface GigabitEthernet1/0/18
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interface GigabitEthernet1/0/19
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interface GigabitEthernet1/0/20
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interface GigabitEthernet1/0/21
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interface GigabitEthernet1/0/22
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interface GigabitEthernet1/0/23
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interface GigabitEthernet1/0/24
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interface GigabitEthernet1/0/25
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interface GigabitEthernet1/0/26
!
interface GigabitEthernet1/0/27
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interface GigabitEthernet1/0/28
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interface GigabitEthernet1/0/29
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interface GigabitEthernet1/0/30
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interface GigabitEthernet1/0/31
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interface GigabitEthernet1/0/32
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interface GigabitEthernet1/0/33
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interface GigabitEthernet1/0/34
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interface GigabitEthernet1/0/35
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interface GigabitEthernet1/0/36
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interface GigabitEthernet1/0/37
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interface GigabitEthernet1/0/38
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interface GigabitEthernet1/0/39
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interface GigabitEthernet1/0/40
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interface GigabitEthernet1/0/41
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interface GigabitEthernet1/0/42
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interface GigabitEthernet1/0/43
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interface GigabitEthernet1/0/44
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interface GigabitEthernet1/0/45
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interface GigabitEthernet1/0/46
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interface GigabitEthernet1/0/47
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interface GigabitEthernet1/0/48
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interface GigabitEthernet1/1/1
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interface GigabitEthernet1/1/2
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interface GigabitEthernet1/1/3
!
interface GigabitEthernet1/1/4
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interface TenGigabitEthernet1/1/1
!
interface TenGigabitEthernet1/1/2
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interface TenGigabitEthernet1/1/3
!
interface TenGigabitEthernet1/1/4
!
interface Vlan1
ip address 10.0.0.251 255.255.255.0
!
ip forward-protocol nd
ip http server
ip http authentication local
ip http secure-server
ip ssh version 2
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!
!
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control-plane
service-policy input system-cpp-policy
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line con 0
stopbits 1
line aux 0
stopbits 1
line vty 0 4
password *******
login local
transport input ssh
line vty 5 15
login local
transport input ssh
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ntp server time.windows.com prefer
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!
end

Flavio Miranda · ‎02-02-2022

Hi

If you did test while run this command, it seems that the interface was almost not used:

eliability 255/255, txload 1/255, rxload 1/255

=================================================

0 output errors, 0 collisions, 2 interface resets
0 unknown protocol drops
0 babbles, 0 late collision, 0 deferred
0 lost carrier, 0 no carrier, 0 pause output
0 output buffer failures, 0 output buffers swapped out

We can see two interface resets but we don´t know how long this log is there. This can be something old. Everything else, looks fine.

================================================

Something that calls my attention is that you disabled portfast, which is not good idea but should be not the cause. And everything else is default, assuming you are using vlan 1 do send your traffic. But, I dont see any interface connected to another device assuming you connected the notebook in one port and the ISP in another port, correct?

Well, if so, I´d say there´s nothing on the switch itself that could justify that behavior. You could try a different switch if possible, upgrade this one to a different IOS or try different ports. Not necessary on this sequence.