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- About sarahr202
12-04-2018
sarahr202
Member since
03-29-2008
Contributor
Created by
sarahr202
in Optical Networking
in Optical Networking
07-13-2018
10:23 PM
07-13-2018
10:23 PM
Hi everyone.
Please consider first scenario ( packet switched network)
CE f0-----------fe PE--rest of network
CE is using CIR 10M CKT, PE has inbound policer for 10 M, bc 2M ( bits).
CE is shaping its traffic to CIR 10M, with matching bc 2M to ensure Policer never get hits and we can see any drops on CE that gets tail dropped.
So far so good.
Now take 2nd scenario with Cisco ONS 1544
CE f0-------f0 PE -SONET ( STS-1)
Above we have packet switched network and SONET ( TDM). CE has CIR of 50M, but PE is not enforcing any policing on f0. So CE can send more than 50M to PE, how does PE deals with traffic more than CIR? In first case, PE can determine if the traffic is exceeding by using burst size, but in 2nd case PE is not using any Policer .
This is my hunch:
1) PE can not determine the if the traffic is exceeding CIR or not when received from CE.
2) Traffic will be queued until it can be transmitted out of SONET interface, traffic will continue to be queued until red drop occurs or tail drops occurs or PE can find the time slot to transmit the queued data in SONET frame.
3) Key thing is PE has no way to determine if the traffic is exceeding, it simply queues the traffic until It can be transmitted in SONET frame or queue gets filled.
I do not know much about SONET , so excuse my ignorance.
Thanks and have a nice weekend!!
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05-16-2018
03:40 PM
Hi everyone.
This is the first time I am dealing with MSDP, have some questions any help will be appreciated!!
Scenario:
Source---R1 200.1.---Dense mode--200.2 -R2----MSDP------R3--Listener
1)Above we R1 and R2 are running Dense mode, R2 is also running MSDP with R3. Normally Rp ( R2) will send SA to MSDP peer if it receives REGISTER. It does nothing if it receives stream from dense mode neighbor or more specifically from dense mode region. What is the minimum config needed to make R2 just do that?
Ok after some research, I can use following on R2 to solve question1:
ip msdp originator-id Loopback0 Where loopback 0 is MSDP IP R2 uses to peer with R2.
SCENARIO#2
Scenario:
Listener---R1 200.1.---Dense mode--200.2 -R2----MSDP------R3--Source 1.1.1.1
236.1.1.1
I want R2 do following:
If R2 receives SA for 236.1.1.1,1.1.1.1, I want R2 to flood it to dense mode neighbor R1
I noticed R2 will only do that if R2 is configured with IP IGMP STATIC JOIN under interface facing R1, but not without it.
Thanks and have a nice day!!
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05-12-2018
12:10 PM
Hi everyone
I would like to hear your thoughts; Please consider the example below:
Lo:1.1.1.1 S1-10.10.10.1----10.2.2.2 R2(rp)<----MSDP----->R3(rp)----->R4 -Listener 235.1.1.1 H S1: Source R2:RP R3:Rp Assume everything is correctly configured. This is what I see: 1) If S1 sends multicast with SRC IP 10.10.10.1 , dst 235.1.1.1, R2 sends SA ( 10.10.10.1, 235.1.1.1) to R3 via MSDP. 2) If S1 sends multicast with SRC IP 1.1.1.1, dst 235.1.1.1, R2 does not send SA for 1.1.1.1, 235.1.1.1, there is no RPF issue, both R2/R3 knows 1.1.1.1 via RPF interface. When I look at RFC 3618 it does not say anything how the R2 should behave if it receives a multicast stream directly i.e from the attached source but SRC IP is not within subnet used between SRC and R2. In our case this is 10.10.10.0/24 but SRC IP in the stream is 1.1.1.1 I see different behavior: Some old IOS just ignores it, some initiates SA. IOS that ignores it: #show version ( emulated GNS3) Cisco IOS Software, 7200 Software (C7200-ADVIPSERVICESK9-M), Version 15.2(4)S5, Cisco C870 ( not emulated) Cisco IOS Software, C870 Software (C870-ADVIPSERVICESK9-M), Version 12.4(24)T8, RELEASE SOFTWARE (fc1)
Thanks and have a nice weekend!!
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05-09-2018
04:56 PM
So Iabbed it up( got access to real gear), just in case if someone in future wants to know: 1) What will R1 do upon receiving ( 1.1.1.1, 235.1.1.1), will it drop it because source IP is not in the same subnet ( i.e 10.10.10.10)? It processes it and built ( S.G) tree towards Source.
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05-09-2018
06:26 AM
Hi everyone,
Scenario#1
Source-10.10.10.10---10.10.10.1 f0/0 R1(rp)--------->rest of multicast network--Listener 235.1.1.1 Assumptions:
R1 has IP sparse mode configured on f0/0, assume rest of multicast config is correct, R1 has ( *,235.1.1.1) in mtable. Source sends a multicast stream with SRC IP 1.1.1.1, 235.1.1.1 ( Source is sourcing it from an IP of loopback) Assume R1 and rest of Multicast network know 1.1.1.1 and rpf checks passes.
With these assumptions in mind, focusing only on R1 ( rp):
1) What will R1 do upon receiving ( 1.1.1.1, 235.1.1.1), will it drop it because source IP is not in the same subnet ( i.e 10.10.10.10)? GNS3 shows very unpredictable behavior sometimes I see R1 passes the traffic, some time it does not so I do not what to believe, unfortunately I do have access to real routers at this time.
Thanks and have a nice day!!
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03-31-2018
09:17 PM
Hi every one,
Please consider the following example:
Cisco Catalyst 3850-12S-S 12
https://www.cdw.com/product/Cisco-Catalyst-3850-12S-S-12-Port-Fast-Ethernet-Switch/3378941#PO
Performance
Type : Forwarding performance
Value : 68.4 Mpps
Type : Stacking bandwidth
Value : 480 Gbps
Type : Switching capacity
Value : 68 Gbps
1)Above what should we go by Switching capacity or forwarding performance of 68.4 Mpps when deciding if the switch can support /provide desired forwarding rate?
Forwarding performance:
What packet size is considered in computing this value of 68.4 Mpps? For example is it Jumbo frame or 64 packet size ?
For example, If we have to look for a switch that can support 40 GIG forwarding rate, and if we look at 68Mpps only , we can arrive at two different conclusions:
Packet size :64byte
68.4x64 Mbyte/sec or around 35g/sec
Switch can not support our target rate.
Packet size: 9000 byte
68.4x9000 M byte/sec or 615 g/sec
Switch exceeds our target rate.
Appreciated !!
Have a nice weekend!!
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03-31-2018
08:22 AM
Thanks, no , we down stream FW will do NAT, 3850 will only be used to get default route from Provider via BGP and announce our IP SPACE via BGP.
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03-30-2018
10:55 PM
Hi everyone,
I hope you all are doing fine.
Below is my requirement:
1) Can support BGP, RSTP/STP, OSPF.
2) we will announce only one summary route to Provider
3) We will receive only default route from Provider
4) We have dual ISP for fail over.
5) Each Provider provides 200M DIA CKT
We have a couple of C3840-24T left over, I am thinking to use them rather than buying new routers.
In our network we use them as ACCESS SWITCHES, but I am thinking why we can not use that for CE as it does meet all our requirement. I just want to get you guys feedback.
Data center to Branch office:
We have 200 M CKT between Data center and our branch office, same requirements:
1) OSPF
2) HQOS
So again I am thinking to use 3850-24T, I understand they are usually used for ACCESS layer, but why I can not use it as it does meet the requirement. Appreciate any feedback!!
Thanks and have a weekend!!
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03-09-2018
06:39 PM
Hi everyone.
Please consider the following example:
(LO:1.1.1.1 )R1-12.12.12.1---12.12.12.2 R2 (LO:2.2.2.2)
Above we are setting MSDP session between R1 and R2. This is what I see:
Case 1:
R1 has a loopback0 : 1.1.1.1/32
ip pim rp-address 1.1.1.1
ip msdp peer 2.2.2.2
I see :
R1 will not initiate TCP session for MSDP
Case2:
R1 has a loopback0 : 1.1.1.1/32
ip pim rp-address 1.1.1.1
ip msdp peer 2.2.2.2 connect-source loopback 0
I see:
R1 initiates TCP session for MSDP.
That tells me MSDP session SRC IP must be same as RP's address on R1
####################
is it normal behavior or am I seeing GNS3 bug?
Additional info:
RFC 3618 does not say anything about SOURCE IP of MSDP session should be same as RP's IP address on the originating peer.
R1#show version Cisco IOS Software, 7200 Software (C7200-ADVENTERPRISEK9-M), Version 15.2(4)S3, RELEASE SOFTWARE (fc1) Technical Support: http://www.cisco.com/techsupport
Thanks and have a nice weekend!!
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02-09-2018
08:51 PM
Hi everyone,
I hope you all are doing fine, I start delving into MSDP..
Please consider the following fictitious scenario:
Assumptions:
Source 1.1.1. is routable among all three companies via static routes. These companies do not own any AS. These companies are not running BGP between R1,R2, R3 either. Currently all routing between these companies are configured using static routes.
We want Multicast stream 235.1.1.1 from source 1.1.1.1 to reach destination machine listening on 235.1.1.1 in Company 3.
1) Do we need to establish MSDP between R1 and R3 as well? or MSDP between R1--R2, MSDP R2--R3 will suffice?
2) Do we need to run BGP between R1,R2,R3 or any IGB will work as well say EIGRP?
Thanks and have a nice weekend!!
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12-03-2017
02:49 PM
Hi everyone,
Please consider the following set up:
ESW4 is both LHR/FHR. This is what I see:
IP PIM DENSE /IP PIM SPARSE-DENSE/ IP PIM sparse commands on the interfaces facing SOURCE/LISTENERS have no impact on multicast forwarding when FHR/LHR is same router.
Above Multicast forwarding refers to when source sends multicast 235.1.1.1, FHR/LHR simply forwards it to LISTENERS regardless of IP PIM mode configured on the interfaces facing SOURCE/LISTENERS.
NOTE: FHR/LHR will send REGISTER for 235.1.1.1 to RP but our focus is specifically on multicast forwarding between INTERFACE facing SOURCE and INTERFACE facing LISTENERS on FHR/LHR.
Configuring of IP PIM regardless of mode on interfaces connected to SOURCE/LISTENERS have no bearing how the PIM router will forward multicast stream to its PIM neighbors.
However, the PIM mode configured on the interface connected to DOWN STREAM neighbor, will determine whether PIM router will use SPARSE logic or dense logic when forwarding stream to DOWN STREAM PIM neighbor.
CASE 1: WHEN INTERFACES FACING SOURCE/LISTENERS are SPARSE MODE:
1) FHR/LHR all interfaces are is SPARSE MODE, FHR/LHR does send PIM JOIN towards RP upon receiving IGMP Report
about 235.1.1.1 from ESW3:
ESW4#show running-config interface s0/0
Building configuration...
Current configuration : 84 bytes
!
interface Serial0/0
ip address 24.24.24.4 255.255.255.0
ip pim sparse-mode
end
ESW4#show running-config interface s0/1
Building configuration...
Current configuration : 84 bytes
!
interface Serial0/1
ip address 43.43.43.4 255.255.255.0
ip pim sparse-mode
Wireshark capture shows PIM JOIN BEING SENT TO RP:
Source generates pings at 235.1.1.1, capture between ESW4 and ESW3 shows , PINGS being forwarded:
2)When INTERFACES FACING SOURCE/LISTENRS are SPARSE -DENSE MODE
ESW4(config)#int s0/0
ESW4(config-if)#ip pim sparse-dense-mode
ESW4(config-if)#int s0/3
ESW4(config-if)#ip pim sparse-dense-mode
No change in behavior, same results:
FHR/LHR still sends PIM JOIN 235.1.1.1 towards RP:
CASE 3: When INTERFACES FACING SOURCE/LISTENERS are configured as DENSE
NO change, same behavior,
PIM JOIN ( *,235.1.1.1) is sent by ESW4 to RP:
Kindly share your thoughts.
Thanks and have a nice evening!!
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11-21-2017
08:37 PM
All that you posted might be normal behavior or might be a bug. It might be wrong configured devices or wrong network engineering or bug (I doubt in it) or all works just as supposed to work.
Yes, REGISTER message must encapsulate multicast packet as a payload and even DR router might send copy of same packet directly to the interface (for local subscribers, for example). Also there are pim-sm protocol design problem when receivers could get duplicating packets for a short period of time mostly when source starts casting.
First of all I am not confused i was very clear what I was look into, your big " might" bolded above is what I observed and wanted to eliminate as it is normal or not.
I ran into GNS3 bug issue but i learned a lot :)
Thanks for your response, have a nice day!!
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Created by
sarahr202
in Optical Networking
07-13-2018 10:23 PM
07-13-2018 10:23 PM
Hi everyone. Please consider first scenario ( packet switched network)
CE f0-----------fe PE--rest o...
05-16-2018 03:40 PM
Hi everyone. This is the first time I am dealing with MSDP, have some
questions any help will be app...
05-12-2018 12:10 PM
Hi everyone I would like to hear your thoughts;Please consider the
example below: Lo:1.1.1.1 S1-10.1...
05-09-2018 04:56 PM
So Iabbed it up( got access to real gear), just in case if someone in
future wants to know:1) What w...
05-09-2018 06:26 AM
Hi everyone, Scenario#1 Source-10.10.10.10---10.10.10.1 f0/0
R1(rp)--------->rest of multicast netwo...
03-31-2018 08:22 AM
Thanks, no , we down stream FW will do NAT, 3850 will only be used to
get default route from Provide...
03-30-2018 10:55 PM
Hi everyone, I hope you all are doing fine. Below is my requirement: 1)
Can support BGP, RSTP/STP, O...
03-09-2018 06:39 PM
Hi everyone. Please consider the following example: (LO:1.1.1.1
)R1-12.12.12.1---12.12.12.2 R2 (LO:2...
02-09-2018 08:51 PM
Hi everyone, I hope you all are doing fine, I start delving into MSDP..
Please consider the followin...
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| Date Registered | 03-29-2008 08:55 AM |
| Date Last Visited | 12-04-2018 05:19 PM |
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