Question:
I've been trying Cisco3925E to find an overall scheme
for understanding what the default interface delay would be across an Ethernet
switching network. Essentially I am trying to fix a network's routing so that
redundancy between sites is achieved via EIGRP metrics rather then via manual
administrative distance adjustments across all infrastructure. There is a long
story here... but one that is not really important towards the point of this
post.
Basically, when looking online I can't
really see a definitive guide saying "Ethernet is 1000usec default
delay". The best I could find is a support forum post
(https://learningnetwork.cisco.com/thread/6116). My point is that when looking
at Nexus switches and some (not all) interfaces on a Cisco Catalyst 3750 the
default interface delay is 10usec rather then the 1000usec suggested elsewhere.
As some examples I have the "show run" segment for some interface and
the "show interface" section of the same interfaces:
interface GigabitEthernet2/0/5
switchport access vlan 700
switchport mode access
spanning-tree portfast
ip dhcp snooping trust
!
interface Vlan700
description Data-Server-01
ip address 10.150.1.1 255.255.255.0
secondary
ip address 10.200.0.1 255.255.255.0
secondary
ip address 10.150.1.252 255.255.255.0
ip helper-address 10.1.0 .27
no ip redirects
no ip unreachables
ip pim sparse-mode
!
3750-CORE#show int gig 2/0/5
GigabitEthernet2/0/5 is down, line protocol
is down (notconnect)
Hardware is Gigabit Ethernet, address is 0026.0ab5.6d85 (bia
0026.0ab5.6d85)
MTU
9000 bytes, BW 10000 Kbit, DLY 1000 usec,
reliability 255/255, txload 1/255, rxload 1/255
Encapsulation ARPA, loopback not set
Keepalive set (10 sec)
Auto-duplex, Auto-speed, media type is 10/100/1000BaseTX
[...]
interface GigabitEthernet4/0/24
no switchport
ip address 10.200.50.254 255.255.255.252
ip summary-address eigrp 1 10.0.0 .0
255.0.0.0
3750-CORE#show int gig 4/0/24
GigabitEthernet4/0/24 is up, line protocol
is up (connected)
Hardware is Gigabit Ethernet, address is 0026.0a95.f141 (bia
0026.0a95.f141)
Internet address is 10.200.50.254/30
MTU
9000 bytes, BW 1000000 Kbit, 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
[...]
interface GigabitEthernet5/0/24
description Telstra Secondary WAN Link
no switchport
ip address 10.200.50.250 255.255.255.252
ip summary-address eigrp 1 10.0.0 .0
255.0.0.0
3750-CORE#show int gig 5/0/24
GigabitEthernet5/0/24 is up, line protocol
is up (connected)
Hardware is Gigabit Ethernet, address is 0026.0a95.f159 (bia
0026.0a95.f159)
Internet
address is 10.200.50.250/30
MTU
9000 bytes, BW 1000000 Kbit, 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
[...]
So all of the above are from the same 3750G
switch stack. The only pattern I can see in the above is that the 10usec NICs
are "routed interfaces" and the 1000usec NICs are
"switchports". In GNS I have a 3700 router setup and all NICs are
1000usec, granted it is a different platform (a router rather then a switch).
Anyone know what the pattern here is? Is
there any reference documents that explain this clearly?
The reason I want to know is that EIGRP is
in use for dynamic routing failover. I need to calculate delay across several
links to provide a deterministic and non-load balanced routing topology (i.e.
active/standby). I'm aware there are likely easier ways to achieve my routing
requirements (OSPF comes to mind) but I'm stuck with a single AS EIGRP topology
for the moment. Summarily, I just want to know about interface delay default
settings.
Answer:
Hello Jonathan,
Great, thanks for all that information..
Really appreciated it
Please mark the question as answered so
future users having the same questions can use it.
Kudos for you For futher information, please refer to http://www.3anetwork.com/cisco-cisco3925e-sec/k9-price_p290.html
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