Solved: Re: QoS on Cico Switches

loc.nguyen · ‎06-22-2024

Hi,

I am working on replacing a switch stack to a new one.

There is a section relate to QoS. I think the old switch has some configuration relates to QoS but it doesn't configure properly. Can I just ignore the config for QoS?

Please advise.

Below is the full configuration of the old switch:

CTT-CORESW#show run
Building configuration...

Current configuration : 19261 bytes
!
!!
version 12.2
no service pad
service timestamps debug datetime msec
service timestamps log datetime msec
service password-encryption
service internal
service unsupported-transceiver
!
hostname CTT-CORESW
!
boot-start-marker
boot-end-marker
!
!
logging buffered 16384

!
!
aaa authentication login default local enable
!
!
!
!
!
aaa session-id common
clock timezone EDT -4 0
switch 1 provision ws-c3750x-48
switch 2 provision ws-c3750x-12s
switch 3 provision ws-c3750x-48
switch 4 provision ws-c3750x-12s
switch 5 provision ws-c3750x-12s
system mtu routing 1500
ip routing
!
ip dhcp excluded-address 10.111.128.1 10.111.130.254
!
ip dhcp pool CANAM_Radios
network 10.111.150.0 255.255.255.0
default-router 10.111.150.1
dns-server 8.8.8.8
lease 30
!
ip dhcp pool State-St
network 10.111.128.0 255.255.252.0
default-router 10.111.128.1
dns-server 8.8.8.8 8.8.4.4
lease 30
!
!
no ip domain-lookup
ip domain-name CTT-CORESW
ip multicast-routing distributed
vtp mode transparent
!
mls qos srr-queue output dscp-map queue 1 threshold 3 56
mls qos srr-queue output dscp-map queue 2 threshold 1 46
mls qos srr-queue output dscp-map queue 3 threshold 1 8
mls qos srr-queue output dscp-map queue 4 threshold 3 0
mls qos queue-set output 1 threshold 1 100 100 100 100
mls qos queue-set output 1 threshold 2 80 90 100 400
mls qos queue-set output 1 threshold 3 100 100 100 400
mls qos queue-set output 1 threshold 4 100 100 100 400
mls qos queue-set output 1 buffers 10 15 25 50
mls qos
password encryption aes
!
crypto pki trustpoint TP-self-signed-300047744
enrollment selfsigned
subject-name cn=IOS-Self-Signed-Certificate-300047744
revocation-check none
rsakeypair TP-self-signed-300047744
!
!
crypto pki certificate chain TP-self-signed-300047744
certificate self-signed 01
3082025A 308201C3 A0030201 02020101 300D0609 2A864886 F70D0101 04050030
30312E30 2C060355 04031325 494F532D 53656C66 2D536967 6E65642D 43657274
69666963 6174652D 33303030 34373734 34301E17 0D393330 33303130 30303132
355A170D 32303031 30313030 30303030 5A303031 2E302C06 03550403 1325494F
532D5365 6C662D53 69676E65 642D4365 72746966 69636174 652D3330 30303437
37343430 819F300D 06092A86 4886F70D 01010105 0003818D 00308189 02818100
AF347BAE F6249E57 4FD3E9B6 90539FE3 01B231D3 D9B0BB89 302AD10F CA1DD19C
27CF1329 E5C06375 E8AF90BC 62C11153 7051F9B3 1313C374 42541EE6 6C587E2E
9247AAE7 5138ADB4 B46D155D 0735CD42 29FE4A42 077AB730 C20A897D BA5CE6CB
4A86E740 B18CECEC 7716FEDC 285D6ACF FA626627 69CFE475 30396210 6872365B
02030100 01A38183 30818030 0F060355 1D130101 FF040530 030101FF 302D0603
551D1104 26302482 22445454 2D434F52 4553572E 4454542D 434F5245 53572E74
72616E73 64796E2E 636F6D30 1F060355 1D230418 30168014 F7A87621 E8180B6D
7A2EDFC4 D6B0E7EF 07BFAD79 301D0603 551D0E04 160414F7 A87621E8 180B6D7A
2EDFC4D6 B0E7EF07 BFAD7930 0D06092A 864886F7 0D010104 05000381 8100283B
67962A46 1298EC41 95FDEF33 9242E7F7 DCB6FB39 697E2003 963E4D6D 1CCE16E7
039AA9F5 FF0EF036 D3B03C41 8BCAD306 52590497 3A63EC9A 9A5ECC6E C883E3A2
FA3ADB3E A76E5113 EAC59E72 EED94DBB 39A4113A 81D8483C 983FD9B4 4DDE9691
C3EFC68C 680DFC65 7783655C DCF1F1D3 36FAFC63 DF5AC3F6 116ED19F 63BB
quit
!
spanning-tree mode mst
spanning-tree extend system-id
!
spanning-tree mst configuration
name BACKBONE
revision 1
!
spanning-tree mst 0-1,8 priority 4096
spanning-tree vlan 11,101-102,104,106 priority 4096
!
!
!
no errdisable detect cause gbic-invalid
!
vlan internal allocation policy ascending
!
vlan 11,42
!
vlan 50
name CanAM-Vlan
!
vlan 104
!
ip ssh time-out 60
ip ssh authentication-retries 2
lldp run
!
class-map match-all CanAM
match ip dscp default cs1 ef cs7
!
!
!
!
!
!
interface FastEthernet0
no ip address
no ip route-cache cef
no ip route-cache
!
interface GigabitEthernet1/0/1
description TEMP: Allow access to switch
switchport access vlan 11
switchport mode access
!
interface GigabitEthernet1/0/2
switchport access vlan 11
switchport mode access
!
interface GigabitEthernet1/0/3
switchport access vlan 11
switchport mode access
!
interface GigabitEthernet1/0/4
switchport access vlan 11
switchport mode access
!
interface GigabitEthernet1/0/5
switchport access vlan 11
switchport mode access
!
interface GigabitEthernet1/0/6
switchport access vlan 11
switchport mode access
!
interface GigabitEthernet1/0/7
switchport access vlan 11
switchport mode access
!
interface GigabitEthernet1/0/8
switchport access vlan 11
switchport mode access
!
interface GigabitEthernet1/0/9
switchport access vlan 11
switchport mode access
!
interface GigabitEthernet1/0/10
description C9300-48T
switchport access vlan 11
switchport mode access
!
interface GigabitEthernet1/0/11
switchport access vlan 11
switchport mode access
!
interface GigabitEthernet1/0/12
switchport access vlan 11
switchport mode access
!
interface GigabitEthernet1/0/13
switchport access vlan 11
switchport mode access
!
interface GigabitEthernet1/0/14
switchport access vlan 11
switchport mode access
!
interface GigabitEthernet1/0/15
switchport access vlan 11
switchport mode access
!
interface GigabitEthernet1/0/16
description "a"
switchport access vlan 11
switchport mode access
!
interface GigabitEthernet1/0/17
switchport access vlan 11
switchport mode access
!
interface GigabitEthernet1/0/18
switchport access vlan 11
switchport mode access
!
interface GigabitEthernet1/0/19
switchport access vlan 11
switchport mode access
!
interface GigabitEthernet1/0/20
switchport access vlan 11
switchport mode access
!
interface GigabitEthernet1/0/21
switchport access vlan 11
switchport mode access
!
interface GigabitEthernet1/0/22
switchport access vlan 11
switchport mode access
!
interface GigabitEthernet1/0/23
switchport access vlan 11
switchport mode access
!
interface GigabitEthernet1/0/24
switchport access vlan 11
switchport mode access
!
interface GigabitEthernet1/0/25
switchport access vlan 11
switchport mode access
!
interface GigabitEthernet1/0/26
switchport access vlan 11
switchport mode access
!
interface GigabitEthernet1/0/27
switchport access vlan 11
switchport mode access
!
interface GigabitEthernet1/0/28
switchport access vlan 11
switchport mode access
!
interface GigabitEthernet1/0/29
switchport access vlan 11
switchport mode access
!
interface GigabitEthernet1/0/30
switchport access vlan 11
switchport mode access
!
interface GigabitEthernet1/0/31
switchport access vlan 11
switchport mode access
!
interface GigabitEthernet1/0/32
switchport access vlan 11
switchport mode access
!
interface GigabitEthernet1/0/33
switchport access vlan 11
switchport mode access
!
interface GigabitEthernet1/0/34
switchport access vlan 11
switchport mode access
!
interface GigabitEthernet1/0/35
switchport access vlan 11
switchport mode access
!
interface GigabitEthernet1/0/36
switchport access vlan 11
switchport mode access
!
interface GigabitEthernet1/0/37
switchport access vlan 11
switchport mode access
!
interface GigabitEthernet1/0/38
switchport access vlan 11
switchport mode access
!
interface GigabitEthernet1/0/39
switchport access vlan 11
switchport mode access
!
interface GigabitEthernet1/0/40
no switchport
ip address 10.111.227.2 255.255.255.252
ip pim sparse-mode
ip ospf cost 10
ip ospf 1 area 0
!
interface GigabitEthernet1/0/41
switchport access vlan 11
switchport mode access
!
interface GigabitEthernet1/0/42
description "Link to Jupiter Video Wall"
switchport access vlan 42
switchport trunk encapsulation dot1q
switchport mode access
!
interface GigabitEthernet1/0/43
switchport access vlan 11
switchport mode access
!
interface GigabitEthernet1/0/44
switchport access vlan 104
switchport trunk encapsulation dot1q
switchport mode access
!
interface GigabitEthernet1/0/45
switchport access vlan 11
switchport mode access
!
interface GigabitEthernet1/0/46
switchport access vlan 11
switchport mode access
!
interface GigabitEthernet1/0/47
switchport access vlan 50
switchport mode access
!
interface GigabitEthernet1/0/48
switchport access vlan 11
switchport mode access
!
interface GigabitEthernet1/1/1
!
interface GigabitEthernet1/1/2
!
interface GigabitEthernet1/1/3
!
interface GigabitEthernet1/1/4
!
interface TenGigabitEthernet1/1/1
!
interface TenGigabitEthernet1/1/2
!
interface GigabitEthernet2/0/1
!
interface GigabitEthernet2/0/2
!
interface GigabitEthernet2/0/3
description "Routed Connection 1"
no switchport
no ip address
ip pim sparse-mode
ip ospf cost 10
ip ospf 1 area 0
!
interface GigabitEthernet2/0/4
!
interface GigabitEthernet2/0/5
!
interface GigabitEthernet2/0/6
!
interface GigabitEthernet2/0/7
!
interface GigabitEthernet2/0/8
!
interface GigabitEthernet2/0/9
!
interface GigabitEthernet2/0/10
!
interface GigabitEthernet2/0/11
!
interface GigabitEthernet2/0/12
!
interface GigabitEthernet2/1/1
!
interface GigabitEthernet2/1/2
!
interface GigabitEthernet2/1/3
!
interface GigabitEthernet2/1/4
!
interface TenGigabitEthernet2/1/1
!
interface TenGigabitEthernet2/1/2
!
interface GigabitEthernet3/0/1
switchport access vlan 11
switchport mode access
!
interface GigabitEthernet3/0/2
switchport access vlan 11
switchport mode access
!
interface GigabitEthernet3/0/3
switchport access vlan 11
switchport mode access
!
interface GigabitEthernet3/0/4
switchport access vlan 11
switchport mode access
!
interface GigabitEthernet3/0/5
switchport access vlan 11
switchport mode access
!
interface GigabitEthernet3/0/6
switchport access vlan 11
switchport mode access
!
interface GigabitEthernet3/0/7
switchport access vlan 11
switchport mode access
!
interface GigabitEthernet3/0/8
switchport access vlan 11
switchport mode access
!
interface GigabitEthernet3/0/9
switchport access vlan 11
switchport mode access
!
interface GigabitEthernet3/0/10
switchport access vlan 11
switchport mode access
!
interface GigabitEthernet3/0/11
switchport access vlan 11
switchport mode access
!
interface GigabitEthernet3/0/12
switchport access vlan 11
switchport mode access
!
interface GigabitEthernet3/0/13
switchport access vlan 11
switchport mode access
!
interface GigabitEthernet3/0/14
switchport access vlan 11
switchport mode access
!
interface GigabitEthernet3/0/15
switchport access vlan 11
switchport mode access
!
interface GigabitEthernet3/0/16
switchport access vlan 11
switchport mode access
!
interface GigabitEthernet3/0/17
switchport access vlan 11
switchport mode access
!
interface GigabitEthernet3/0/18
switchport access vlan 11
switchport mode access
!
interface GigabitEthernet3/0/19
switchport access vlan 11
switchport mode access
!
interface GigabitEthernet3/0/20
switchport access vlan 11
switchport mode access
!
interface GigabitEthernet3/0/21
switchport access vlan 11
switchport mode access
!
interface GigabitEthernet3/0/22
switchport access vlan 11
switchport mode access
!
interface GigabitEthernet3/0/23
switchport access vlan 11
switchport mode access
!
interface GigabitEthernet3/0/24
switchport access vlan 11
switchport mode access
!
interface GigabitEthernet3/0/25
switchport access vlan 11
switchport mode access
!
interface GigabitEthernet3/0/26
switchport access vlan 11
switchport mode access
!
interface GigabitEthernet3/0/27
switchport access vlan 11
switchport mode access
!
interface GigabitEthernet3/0/28
switchport access vlan 11
switchport mode access
!
interface GigabitEthernet3/0/29
switchport access vlan 11
switchport mode access
!
interface GigabitEthernet3/0/30
switchport access vlan 11
switchport mode access
!
interface GigabitEthernet3/0/31
switchport access vlan 11
switchport mode access
!
interface GigabitEthernet3/0/32
switchport access vlan 11
switchport mode access
!
interface GigabitEthernet3/0/33
switchport access vlan 11
switchport mode access
!
interface GigabitEthernet3/0/34
switchport access vlan 11
switchport mode access
!
interface GigabitEthernet3/0/35
switchport access vlan 11
switchport mode access
!
interface GigabitEthernet3/0/36
switchport access vlan 11
switchport mode access
!
interface GigabitEthernet3/0/37
switchport access vlan 11
switchport mode access
!
interface GigabitEthernet3/0/38
switchport access vlan 11
switchport mode access
!
interface GigabitEthernet3/0/39
switchport access vlan 11
switchport mode access
!
interface GigabitEthernet3/0/40
no switchport
ip address 172.27.255.210 255.255.255.252
ip pim sparse-mode
ip ospf 1 area 0
!
interface GigabitEthernet3/0/41
switchport access vlan 11
switchport mode access
!
interface GigabitEthernet3/0/42
switchport access vlan 42
switchport mode access
!
interface GigabitEthernet3/0/43
switchport access vlan 42
switchport mode access
!
interface GigabitEthernet3/0/44
switchport access vlan 11
switchport mode access
!
interface GigabitEthernet3/0/45
switchport access vlan 11
switchport mode access
!
interface GigabitEthernet3/0/46
switchport access vlan 11
switchport mode access
!
interface GigabitEthernet3/0/47
switchport access vlan 50
switchport mode access
!
interface GigabitEthernet3/0/48
description CTT-CanAM
switchport access vlan 50
switchport mode access
srr-queue bandwidth share 10 15 25 50
priority-queue out
mls qos trust dscp
!
interface GigabitEthernet3/1/1
!
interface GigabitEthernet3/1/2
!
interface GigabitEthernet3/1/3
!
interface GigabitEthernet3/1/4
!
interface TenGigabitEthernet3/1/1
!
interface TenGigabitEthernet3/1/2
!
interface GigabitEthernet4/0/1
description "Routed Connection to HUB01-HM01"
no switchport
ip address 10.111.225.17 255.255.255.252
ip pim sparse-mode
ip ospf cost 10
ip ospf 1 area 0
!
interface GigabitEthernet4/0/2
description "Routed Connection to HUB08-HM01"
no switchport
ip address 10.111.225.21 255.255.255.252
ip pim sparse-mode
ip ospf cost 10
ip ospf 1 area 0
!
interface GigabitEthernet4/0/3
!
interface GigabitEthernet4/0/4
!
interface GigabitEthernet4/0/5
description "Routed Connection to MTTCORE-SW"
no switchport
ip address 10.111.227.9 255.255.255.252
ip pim sparse-mode
ip ospf cost 1
ip ospf 1 area 0
!
interface GigabitEthernet4/0/6
!
interface GigabitEthernet4/0/7
!
interface GigabitEthernet4/0/8
!
interface GigabitEthernet4/0/9
no switchport
no ip address
ip pim sparse-mode
ip ospf cost 10
ip ospf 1 area 0
!
interface GigabitEthernet4/0/10
description "Routed Connection to HUBDTT-HM01"
no switchport
ip address 10.111.225.9 255.255.255.252
ip pim sparse-mode
ip ospf cost 10
ip ospf 1 area 0
!
interface GigabitEthernet4/0/11
!
interface GigabitEthernet4/0/12
!
interface GigabitEthernet4/1/1
!
interface GigabitEthernet4/1/2
!
interface GigabitEthernet4/1/3
!
interface GigabitEthernet4/1/4
!
interface TenGigabitEthernet4/1/1
!
interface TenGigabitEthernet4/1/2
!
interface GigabitEthernet5/0/1
description "Routed Connection to HUB03-HM01"
no switchport
ip address 10.111.225.1 255.255.255.252
ip pim sparse-mode
ip ospf cost 10
ip ospf 1 area 0
!
interface GigabitEthernet5/0/2
description "Routed Connection to HUB04-HM01"
no switchport
ip address 10.111.225.5 255.255.255.252
ip pim sparse-mode
ip ospf cost 10
ip ospf 1 area 0
!
interface GigabitEthernet5/0/3
!
interface GigabitEthernet5/0/4
description "Routed Connection "
no switchport
ip address 10.111.225.29 255.255.255.252
ip pim sparse-mode
ip ospf cost 10
ip ospf 1 area 0
!
interface GigabitEthernet5/0/5
description "Routed Connection"
no switchport
ip address 10.111.225.33 255.255.255.252
ip pim sparse-mode
ip ospf cost 10
ip ospf 1 area 0
!
interface GigabitEthernet5/0/6
shutdown
!
interface GigabitEthernet5/0/7
!
interface GigabitEthernet5/0/8
!
interface GigabitEthernet5/0/9
!
interface GigabitEthernet5/0/10
switchport access vlan 50
switchport mode access
srr-queue bandwidth share 10 15 25 50
priority-queue out
mls qos trust dscp
!
interface GigabitEthernet5/0/11
!
interface GigabitEthernet5/0/12
description "Routed Connection to HUB06-HM01"
no switchport
ip address 10.111.225.13 255.255.255.252
ip pim sparse-mode
ip ospf cost 10
ip ospf 1 area 0
!
interface GigabitEthernet5/1/1
!
interface GigabitEthernet5/1/2
!
interface GigabitEthernet5/1/3
!
interface GigabitEthernet5/1/4
!
interface TenGigabitEthernet5/1/1
!
interface TenGigabitEthernet5/1/2
!
interface Vlan1
no ip address
!
interface Vlan11
description "CTT Operations Center"
ip address 10.111.128.1 255.255.252.0
ip pim sparse-mode
!
interface Vlan42
description "Jupiter Video Wall Vlan"
ip address 10.111.142.1 255.255.255.0
ip pim sparse-mode
ip ospf cost 10
ip ospf 1 area 0
!
interface Vlan50
ip address 10.111.150.1 255.255.255.0
ip ospf cost 10
ip ospf 1 area 0
!
interface Vlan104
description TEMP TEMP TEMP Connection to LFC-01 through 05
ip address 10.111.4.1 255.255.255.0
ip pim sparse-mode
shutdown
!
router ospf 1
router-id 10.111.224.1
auto-cost reference-bandwidth 10000
redistribute static subnets
network 10.111.128.0 0.0.3.255 area 0
network 10.111.225.0 0.0.0.255 area 0
default-information originate
!
!
ip http server
ip http secure-server
!
ip pim rp-address 10.10.254.34 HRTOC-MC override
ip pim bsr-candidate Vlan11 1 192
ip pim rp-candidate Vlan11 group-list MC
ip route 0.0.0.0 0.0.0.0 10.111.227.1
ip route 10.10.248.0 255.255.255.0 172.27.255.209
ip route 10.10.249.0 255.255.255.0 172.27.255.209
ip route 10.10.254.0 255.255.255.0 172.27.255.209
ip route 172.26.0.0 255.254.0.0 172.27.255.209
ip route 192.168.1.0 255.255.255.0 10.111.227.1
ip route 192.168.17.0 255.255.255.0 172.27.255.209
!
ip access-list standard xxx-MC
permit 239.5.0.0 0.0.3.255
ip access-list standard xxx-MC
permit 239.101.0.0 0.0.255.255
!
logging esm config
logging source-interface Vlan11
logging 192.168.1.126
!
snmp-server group OPENNMS v2c
snmp-server community MTTDTT RO
snmp-server enable traps snmp authentication linkdown linkup coldstart warmstart
snmp-server enable traps ospf state-change
snmp-server enable traps ospf errors
snmp-server enable traps ospf retransmit
snmp-server enable traps ospf lsa
snmp-server enable traps ospf cisco-specific state-change nssa-trans-change
snmp-server enable traps ospf cisco-specific state-change shamlink interface
snmp-server enable traps ospf cisco-specific state-change shamlink neighbor
snmp-server enable traps ospf cisco-specific errors
snmp-server enable traps ospf cisco-specific retransmit
snmp-server enable traps ospf cisco-specific lsa
snmp-server enable traps config
snmp-server enable traps pim neighbor-change rp-mapping-change invalid-pim-message
snmp-server enable traps syslog
snmp-server enable traps stackwise
snmp-server host 10.111.128.110 version 2c xxx ospf pim stackwise
!
!
!
!
line con 0
line vty 0 4
exec-timeout 60 0
length 0
transport input telnet ssh
line vty 5 15
exec-timeout 60 0
transport input telnet ssh
!
!
monitor session 1 source interface Gi1/0/42
ntp source Vlan11
ntp server 10.111.128.110 prefer
end

CTT-CORESW#

Joseph W. Doherty · ‎06-25-2024

@loc.nguyen wrote:

I also see the config:

"interface GigabitEthernet3/0/48
description CTT-CanAM
switchport access vlan 50
switchport mode access
srr-queue bandwidth share 10 15 25 50
priority-queue out
mls qos trust dscp"

This one I need copy it to new switch, right?

Again, it would depend on your QoS needs.

The defaults and QoS architecture differ between the old and newer switches.

For example, on the older switches, QoS was totally disabled, by default, and if enabled, without "mls qos trust dscp", ToS would be reset to zero.

The older switches often had just 4 egress queues, newer switches, often now have 8 egress queues.

Two of the older switch's interface QoS commands adjust bandwidth dequeuing ratios and set one queue to PQ. This can be done on the newer switches too, but syntax is HQF, i.e. set via a policy-map.

The way I recommend building QoS device configurations, first start with a logical QoS policy you want to provide. Then, on any platform, you can try to use its QoS features to come as close to the logical QoS policy as possible.

From you newly posted information, I can say, someone changed the default QoS settings, so again, what was the QoS goal?

View solution in original post

Joseph W. Doherty · ‎06-22-2024

"Can I just ignore the config for QoS?"

Depends on whether you really needed the prior QoS.

Your old config shows what was done, but not why it was done.

loc.nguyen · ‎06-25-2024

I see setttings:

"mls qos srr-queue output dscp-map queue 1 threshold 3 56
mls qos srr-queue output dscp-map queue 2 threshold 1 46
mls qos srr-queue output dscp-map queue 3 threshold 1 8
mls qos srr-queue output dscp-map queue 4 threshold 3 0
mls qos queue-set output 1 threshold 1 100 100 100 100
mls qos queue-set output 1 threshold 2 80 90 100 400
mls qos queue-set output 1 threshold 3 100 100 100 400
mls qos queue-set output 1 threshold 4 100 100 100 400
mls qos queue-set output 1 buffers 10 15 25 50
mls qos"

I don't see these settings apply to any interfaces. So they are uesless, aren't they?

loc.nguyen · ‎06-25-2024

I also see the config:

"interface GigabitEthernet3/0/48
description CTT-CanAM
switchport access vlan 50
switchport mode access
srr-queue bandwidth share 10 15 25 50
priority-queue out
mls qos trust dscp"

This one I need copy it to new switch, right?

Joseph W. Doherty · ‎06-25-2024

@loc.nguyen wrote:

I also see the config:

"interface GigabitEthernet3/0/48
description CTT-CanAM
switchport access vlan 50
switchport mode access
srr-queue bandwidth share 10 15 25 50
priority-queue out
mls qos trust dscp"

This one I need copy it to new switch, right?

Again, it would depend on your QoS needs.

The defaults and QoS architecture differ between the old and newer switches.

For example, on the older switches, QoS was totally disabled, by default, and if enabled, without "mls qos trust dscp", ToS would be reset to zero.

The older switches often had just 4 egress queues, newer switches, often now have 8 egress queues.

Two of the older switch's interface QoS commands adjust bandwidth dequeuing ratios and set one queue to PQ. This can be done on the newer switches too, but syntax is HQF, i.e. set via a policy-map.

The way I recommend building QoS device configurations, first start with a logical QoS policy you want to provide. Then, on any platform, you can try to use its QoS features to come as close to the logical QoS policy as possible.

From you newly posted information, I can say, someone changed the default QoS settings, so again, what was the QoS goal?

loc.nguyen · ‎06-26-2024

Thanks. I don't know what the goal of the old set up. This system was set up 10 years ago and noboby took care of it. I was assgined to replace the switch stack with the new one.

Joseph W. Doherty · ‎06-25-2024

@loc.nguyen wrote:

I see setttings:

"mls qos srr-queue output dscp-map queue 1 threshold 3 56
mls qos srr-queue output dscp-map queue 2 threshold 1 46
mls qos srr-queue output dscp-map queue 3 threshold 1 8
mls qos srr-queue output dscp-map queue 4 threshold 3 0
mls qos queue-set output 1 threshold 1 100 100 100 100
mls qos queue-set output 1 threshold 2 80 90 100 400
mls qos queue-set output 1 threshold 3 100 100 100 400
mls qos queue-set output 1 threshold 4 100 100 100 400
mls qos queue-set output 1 buffers 10 15 25 50
mls qos"

I don't see these settings apply to any interfaces. So they are uesless, aren't they?

No they aren't useless. They modify QoS parameters for a set of like kind of interfaces on the 2960/3560/3750 series, instead of just per interface settings.

Leo Laohoo · ‎06-22-2024

QoS configuration from classic IOS, for platforms like the 3750X, is incompatible with IOS-XE, for platforms like the 3650/3850 & Catalyst 9000 switches.

The most important configuration that need is:

qos queue-softmax-multiplier 1200

Start with that command and configure &/or modify the default or pre-defined QoS IOS-XE settings when necessary and not "because it was already there in the old switch".