From 4d24fca821b71d5b309ca3c9d746550e65d55931 Mon Sep 17 00:00:00 2001 From: shango-wk Date: Tue, 2 Jun 2026 09:35:28 +0200 Subject: [PATCH] ajout Etherchannel --- 00. Jeremy's IT LAB CCNA course.md | 2 + 22 Rapid Spanning Tree Protocol.md | 185 +++++++++++++++++++++++++++++ 23. EtherChannel.md | 128 ++++++++++++++++++++ 3 files changed, 315 insertions(+) create mode 100644 22 Rapid Spanning Tree Protocol.md create mode 100644 23. EtherChannel.md diff --git a/00. Jeremy's IT LAB CCNA course.md b/00. Jeremy's IT LAB CCNA course.md index a827c1a..441077f 100644 --- a/00. Jeremy's IT LAB CCNA course.md +++ b/00. Jeremy's IT LAB CCNA course.md @@ -34,3 +34,5 @@ tags: [[PortFast (STP Toolkit)]] [[BPDU Guard & BPDU Filter (STP Toolkit)]] [[Root Guard (STP Toolkit)]] +[[Rapid Spanning Tree Protocol]] +[[EtherChannel]] diff --git a/22 Rapid Spanning Tree Protocol.md b/22 Rapid Spanning Tree Protocol.md new file mode 100644 index 0000000..4b17446 --- /dev/null +++ b/22 Rapid Spanning Tree Protocol.md @@ -0,0 +1,185 @@ +--- +id: 22 Rapid Spanning Tree Protocol +aliases: [] +tags: + - CCNA +--- + +# Rapid Spanning Tree Protocol + +## Spanning Tree Version + +### Industry standards (IEEE) + +Spanning Tree Protocol (802.1D) +- The original STP +- ALl VLANs share one STP instance. +- Therefore, cannot load balance. + +Rapid spanning Tree Protocol (802.1w) +- Much faster at converging/adaptating to network changes than 802.1D +- All VLANs share one STP instance. +- Therefore, cannot load balance + +Multiple Spanning Tree Protocol (802.1s) +- Uses modified RSTP mechanics. +- Can group multiple VLANs into different instacnces (ie. VLANs 1-5 instance 1, VLANs 6-10 in instance +2 ) to perform load balancing + +### CISCO Versions + +Per-VLAN Spanning Tree Plus (PVST+) +- Cisco's upgrade to 802.1D +- Each VLAN has its own STP instance. +- Can load balance by blocking different ports in each VLAN. + +Rapid Per-VLAN Spanning Tree Plus (Rapid PVST+) +- Cisco's upgrade to 802.1w +- Each VLAN has its own STP instance +- Can load balance by blocking different ports in each VLAN + +## Rapid spanning Tree Protocol + +Cisco's summary: +"RSTP is not a timer-based spanning tree algorithm like 802.1D. therefore, RSTP offers an improvement +over the 30 seconds or more that 902.1d takes to move a link to forwarding. the heart of +the protocol is new bridge-bridge handshake mechanism, which allows ports to move directly to forwarding." + +### Similarities between STP and RSTP: + +RSTP serves the same purpoe as STP, blocking specific ports to prevent Layer2 loops. +- RSTP elect a root bridge with same rules as STP +- RSTP elects root ports with the same rules as STP. +- RSTP elects designated ports with the same rules as STP + +### Differences + +#### COST + +| speed | STP COST | STP COST | +| -------------- | --------------- | --------------- | +| 10 Mbps | 100 | 2,000,000 | +| 100 Mbps | 19 | 200,000 | +| 1 Gbps | 4 | 20,000 | +| 10 Gbps | 2 | 2,000 | +| 100 Gbps | x | 200 | +| 1 Tbps | x | 20 | + + +#### Port State + +| STP Port State | Send/Receive BPDUs | Frame Forwarding | MAC Learning | Stable/Transitional | +| ------------- | -------------- | -------------- | -------------- | -------------- | +| Discarding | NO/YES | NO | NO | Stable | +| Learing | YES/YES | NO | YES | Tranisitional | +| Forwarding | YES/YES | YES | YES | Stable | + + +- if a port is administratively disabled (shutdown command) = discarding state +- if a port is enabled but blocking traffic to prevent Layer 2 loops = discarding state + +#### Port Roles + +*The root port role remains unchanged in RSTP.* +- The port wthat is closet to the root bridge becomes the root port for the switch. +- The root bridge is the only switch that doesn't have a root port. + +*The designated port role remains unchanged in RSTP.* +- The port on a segment (collision domain) that sends the best BPDU is that +segment's designated port (only one per segment) + +- *The non designated port role is split into two separate roles in RSTP*: + - The alternate port role + - the backup port role + +##### Alternate port Role + +The RSTP alternate port role is discarding port that receives a superior BPDU from another switch. +- This is the same as what you've learned about *blocking* ports in classic STP. +- Functions as a backup to the root port. +- If the root port fails, the switch can immediately move its best alternate port to forwarding + + This immediate move to fowarding state functions like a classic STP optional feature called + UplinkFast. Because it is built into RSTP, you do not need to activate UplinkFast when using + RSTP/Rapid PVST+ + + One more STP optional feature that was built into RSTP is BackboneFast. + Backbone Fast allows SW3 to expire the made age timers on its interface and rapidly forward the superior + BPDUs to SW2. + This functionality is built into RSTP, so it does not need to be configured + +##### Backup port role + +The RSTP backup port role is a discarding port that receives a superior BPDU from another +interface on the same switch. +- This only happnes when two interfaces are connected to the same collision domain (via a hub) +- Hubs are not used in modern networks, so you will probably not encounter an RSTP backup port. +- Function as backup for a designated port +- The interface with the lowest port ID will be selected as the designated port and the other will be the +backup port + +### BPDU + +In classic [[STP]], only the root bridge originated BPDUs, and other switches just forwarded the BPDUs +they received. +In Rapid STP, all Switches originate and send their own BPDUs from their designated ports + +All switches running Rapid STP send their own BPDUs every hello time (2 seconds). +- Switches 'age' the BPDU information much more quickly, in classic STP a switch waits 10 hello intervales +(20 seconds). In rapid STP, a switch considers a neighbor lost if it misses 3 BPDUs (6 seconds) +It will the 'Flush' All MAV addresses learned on that interface + +## RSTP Link Types + +RSTP distiguishes between three different 'link types' +- Edge: a port that is connected to an end host. Moves directly to forwarding without negotiation. +- Point-to-point: a direct connection between two switches +- Shared a connection to a [[hub]]. Must operate in half-duplex mode. + +### Edge + +Edge ports are connected to end hosts. +- Because ther is no risk of creating a loop, they can move stright to the forwarding state without the +negotiation process. +- They function like a classic STP port with PortFast enabled + +```Cisco +SW1(config-if)# spanning-tree portfast +``` + +### Point-to-Point + +Point-to-point ports connect directly to another switch +- They function in full-duplex +- you don't need to configure the interface as point-to-point (it should be detected) + +```Cisco +SW1(config-if)# spanning-tree link-type point-to-point +``` + + +### Shared + +shared Ports connect to another switch (or switches) via a hub. +- They function in half-duplex +- You don't need to configure the interface as shared (it should be detected) + +```Cisco +SW1(config-if)# spanning-tree link-type shared +``` + +### Configuration + + +```Cisco +SW3(config)# spanning-tree mode rapid-pvst + +SW3(config)# do show spanning-tree +``` + + +## Review + +Comparison of [[STP]] versions (standard vs [[Cisco]]) + +Rapid PVST+ diff --git a/23. EtherChannel.md b/23. EtherChannel.md new file mode 100644 index 0000000..6afd66b --- /dev/null +++ b/23. EtherChannel.md @@ -0,0 +1,128 @@ +--- +id: 23. EtherChannel +aliases: [] +tags: [] +--- + +# EtherChannel + +multiple host -- ASW1 -- DSW1 + +ASW = Access layer Switch, a switch that end hosts connect to +DSW = Distribution layer switch, a switch that access layer switches connect to + +When the bandwith of the interfaces connected to end hosts is greater than the bandwidth of the +connection to the distribution switch(es), this is called *oversubscription*. +Some oversubscription is acceptable, but too much will cause congestion. + +- if you connect two switchs together with multiple links, all except one will be disabled by +[[spanning tree]] +- if all of ASW1's interfaces were forwarding, Layer 2 loops would form between ASW1 and DSW1, +leading to [[broadcast storms]]. +- Other links will be unused unless the active link fails. in that case one of the inactive +links will start forwarding +- EtherChannel groups multiple interfaces together to act as a single interface. +- STP will treat this group as a single interface + +Traffic using the EtherChannel wil be load balanced among the physical interfaces in the group. +An [[algorithm]] is used to determine which traffic will use which physical interface. + +Some other names for an EtherChannel are: +- Port Channel +- LAG (Link aggregaton Group) + +## Load Balancing + +- EtherChannel load balances based on flows +- A flow is a communication between two nodes in the network +- Frames in the same flow will be forwarded using the same physicial interface. +- If frames in the same flow were forwarded using different physical interfaces, some frames +may arrive at the destination out of order, which can cause problems +- You can change the inputs used in the interface selection calculation. +- Inputs that can be used: + - Source [[MAC]] + - Destination MAC + - Source and Destination MAC + - Source [[IP]] + - Destination IP + - Source and Destination IP + +### Commands + + +see current configuration +```Cisco +ASW1#show etherchannel load-balance +### default will be set to src-dst-ip +``` + +for configuring load balance configuration +```Cisco +ASW1(config)#port-channel load-balance src-dst-mac + +## to see other method +ASW1(config)#port-channel load-balance ? +``` + +## EtherChannel Configuration + +There are three methods of EtherChannel configuration on Cisco switches: +- PAgP (Port Aggregation Protocol) + - Cisco proprietary protocol + - Dynamically negotiates the creation/maintenance of the EtherChannel. + (like DTP does for trunks) +- LACP (Link Aggregation Control Protocol) + - Industry standard protocol (IEEE 802.3ad) + - Dynamically negotiate the creation/maintenance of the EtherChannel. + (like DTP does for trunks) +- Static EtherChannel + - A protocol isn't used to determine if an EtherChannel should be formed. + - Interfaces are statically configured to form an EtherChannel + +Up to *8 interfaces* can be formed into a single EtherChannel (LACP allows up to 16, but only +8 will be active, the other 8 will be in standby mode, waiting for an active interface to fail) + +```Cisco +ASW1(config)#inteface range g0/0 - 3 +## to see all methods +ASW1(config-if-range)#channel-group 1 mode ? +## for PAgP +ASW1(config-if-range)#channel-group 1 mode desirable +``` + + note: The channel-group number has to match for member interfaces on the same switch. + However, it doesn't have to match the channel-group number on the other switch. + (channel-group 1 on ASW1 can form an EhterChannel with channel-group 2 on DSW1) + +Member intefaces must have matching configurations. +- Same duplex (full/half) +- Same speed +- Same switchport mode (access/trunk) +- Same allowed VLANs/native VLAN (for trunk interfaces) + +If an interface's configurations do not match the others, it will be excluded from the EtherChannel + +to see running configuration of the EtherChannel + +```Cisco +ASW1#show etherchannel summary +## less utilise command +ASW1#show etherchannel port-channel +``` + +## Layer 3 EtherChannel + +```Cisco +ASW1(config)#int range g0/0 - 3 +ASW1(config-if-range)#no switchport +ASW1(config-if-range)#channel-group 1 mode active + + +ASW1(config-if-range)#int po1 +ASW1(config-if)#ip address 10.0.0.1 255.255.255.252 +``` + +## Review + +- What is EtherChannel? what problems does it solve? +- Configuring Layer 2/Layer 3 EtherChannel