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Tagged with #switch
1/10/2023

Broadcast Storm by Ryo

#switch

Tagged with #switch #STP #CCNA
1/8/2023

Redundant Links and STP by Ryo

#switch #STP #CCNA

Hi! Today, I tested STP with my two switches by simply connecting them with two cables. As shown below, one of the links belonging to the non-root bridge got blocked based on the priority number. pi#show spanning-tree vlan 1 VLAN0001 Spanning tree enabled protocol ieee Root ID Priority 32769 Address ec30.918e.c100 Cost 19 Port 5 (FastEthernet0/3) Hello Time 2 sec Max Age 20 sec Forward Delay 15 sec Bridge ID Priority 32769 (priority 32768 sys-id-ext 1) Address f029.2952.8d80 Hello Time 2 sec Max Age 20 sec Forward Delay 15 sec Aging Time 300 sec Interface Role Sts Cost Prio.Nbr Type ------------------- ---- --- --------- -------- -------------------------------- Fa0/1 Desg FWD 19 128.3 P2p Fa0/3 Root FWD 19 128.5 P2p Fa0/5 Altn BLK 19 128.7 P2p As the above shows, Fa0/3 is the root port connected to the switch on the other end. So I plugged it out to see if the connection remains up by changing the root port to Fa0/5. Below is the result. pi>show spanning-tree vlan 1 VLAN0001 Spanning tree enabled protocol ieee Root ID Priority 32769 Address ec30.918e.c100 Cost 19 Port 7 (FastEthernet0/5) Hello Time 2 sec Max Age 20 sec Forward Delay 15 sec Bridge ID Priority 32769 (priority 32768 sys-id-ext 1) Address f029.2952.8d80 Hello Time 2 sec Max Age 20 sec Forward Delay 15 sec Aging Time 15 sec Interface Role Sts Cost Prio.Nbr Type ------------------- ---- --- --------- -------- -------------------------------- Fa0/1 Desg FWD 19 128.3 P2p Fa0/5 Root LIS 19 128.7 P2p As expected, Fa0/5 is now the root port and the connection is still up! However, one drawback of this configuration is that one of the links is left unused. In order to utilize both of the links, I can set up an etherchannel and bundle the two links. I'm currently studying etherchannel to actually test it out and see how it differs from simply connected redundant links🧐.

Tagged with #router #switch #CCNA
1/3/2023

Inter VLAN Routing by Ryo

#router #switch #CCNA

Hi! Today, I was working on Inter VLAN Routing using a router(800) and L2 switch(Catalyst 2960). I connected a PC to each VLAN(VLAN10, VLAN20) and tested if I can ping to each other. Below is the set up for the PCs(Windows, Raspberry Pi) connected to the switch. The ip address for the Windows PC is 192.168.1.2/24 and the gateway address for 192.168.2.0/24 is 192.168.1.1/24. For Raspberry Pi, its ip address is 192.168.2.2/24 and the gateway address for 192.168.1.0/24 is 192.168.2.1/24. C:\WINDOWS\system32>route add 192.168.2.0 mask 255.255.255.0 192.168.1.1 OK! ┌──(kali㉿kali-raspberry-pi)-[~] └─$ sudo ifconfig eth0 192.168.2.2 ┌──(kali㉿kali-raspberry-pi)-[~] └─$ sudo ip route add 192.168.1.0/255.255.255.0 via 192.168.2.1 dev eth0 onlink ┌──(kali㉿kali-raspberry-pi)-[~] └─$ route -n Kernel IP routing table Destination Gateway Genmask Flags Metric Ref Use Iface 0.0.0.0 192.168.164.146 0.0.0.0 UG 600 0 0 wlan0 192.168.1.0 192.168.2.1 255.255.255.0 UG 0 0 0 eth0 192.168.2.0 192.168.2.1 255.255.255.0 UG 0 0 0 eth0 192.168.164.0 0.0.0.0 255.255.255.0 U 600 0 0 wlan0 Then I configured the switch. I prepared vlan10 & vlan20 for the Windows PC & Raspberry Pi, respectively. After finishing setting up vlans, you need to assign ports to the respective vlans. This time, I used 4 cables, two for connecting the PCs to the switch and the other two for connecting the router. Here are the commands I used for creating vlans. Switch>enable Switch#config terminal Enter configuration commands, one per line. End with CNTL/Z. Switch(config)#vlan 10 Switch(config-vlan)#vlan 20 Switch(config-vlan)#do show vlan VLAN Name Status Ports ---- -------------------------------- --------- ------------------------------- 1 default active Fa0/1, Fa0/2, Fa0/3, Fa0/4 Fa0/5, Fa0/6, Fa0/7, Fa0/8 Fa0/9, Fa0/10, Fa0/11, Fa0/12 Fa0/13, Fa0/14, Fa0/15, Fa0/16 Fa0/17, Fa0/18, Fa0/19, Fa0/20 Fa0/21, Fa0/22, Fa0/23, Fa0/24 Gi0/1, Gi0/2 10 VLAN0010 active 20 VLAN0020 active 1002 fddi-default act/unsup 1003 token-ring-default act/unsup 1004 fddinet-default act/unsup 1005 trnet-default act/unsup Next I assigned the ports to the respective vlans. Switch(config)#do show vlan VLAN Name Status Ports ---- -------------------------------- --------- ------------------------------- 1 default active Fa0/1, Fa0/2, Fa0/3, Fa0/4 Fa0/5, Fa0/6, Fa0/7, Fa0/8 Fa0/9, Fa0/10, Fa0/11, Fa0/12 Fa0/13, Fa0/14, Fa0/15, Fa0/16 Fa0/17, Fa0/18, Fa0/19, Fa0/20 Fa0/21, Fa0/22, Fa0/23, Fa0/24 Gi0/1, Gi0/2 10 VLAN0010 active 20 VLAN0020 active 1002 fddi-default act/unsup 1003 token-ring-default act/unsup 1004 fddinet-default act/unsup 1005 trnet-default act/unsup VLAN Type SAID MTU Parent RingNo BridgeNo Stp BrdgMode Trans1 Trans2 ---- ----- ---------- ----- ------ ------ -------- ---- -------- ------ ------ 1 enet 100001 1500 - - - - - 0 0 10 enet 100010 1500 - - - - - 0 0 20 enet 100020 1500 - - - - - 0 0 1002 fddi 101002 1500 - - - - - 0 0 Switch(config)#interface fa0/1 Switch(config-if)# 00:02:41: %CDP-4-NATIVE_VLAN_MISMATCH: Native VLAN mismatch discovered on FastEthernet0/3 (1), with Router FastEthernet0 (10). Switch(config-if)# 00:02:47: %CDP-4-NATIVE_VLAN_MISMATCH: Native VLAN mismatch discovered on FastEthernet0/5 (1), with Router FastEthernet1 (20). Switch(config-if)#switchport mode access Switch(config-if)#switchport access vlan 10 Switch(config-if)#interface fa0/2 Switch(config-if)#switchport mode access Switch(config-if)#switchport access vlan 20 Switch(config-if)# 00:03:36: %CDP-4-NATIVE_VLAN_MISMATCH: Native VLAN mismatch discovered on FastEthernet0/3 (1), with Router FastEthernet0 (10). Switch(config-if)#interface fa0/3 Switch(config-if)#switchport access vlan 20 00:03:42: %CDP-4-NATIVE_VLAN_MISMATCH: Native VLAN mismatch discovered on FastEthernet0/5 (1), with Router FastEthernet1 (20). Switch(config-if)#switchport mode access Switch(config-if)#switchport access vlan 10 Switch(config-if)#interface fa0/5 Switch(config-if)#switchport mode access Switch(config-if)#switchport access vlan 20 Switch(config-if)#switchport access vlan 20 00:04:10: %LINEPROTO-5-UPDOWN: Line protocol on Interface Vlan1, changed state tmode access Switch(config-if)#do show vlan VLAN Name Status Ports ---- -------------------------------- --------- ------------------------------- 1 default active Fa0/4, Fa0/6, Fa0/7, Fa0/8 Fa0/9, Fa0/10, Fa0/11, Fa0/12 Fa0/13, Fa0/14, Fa0/15, Fa0/16 Fa0/17, Fa0/18, Fa0/19, Fa0/20 Fa0/21, Fa0/22, Fa0/23, Fa0/24 Gi0/1, Gi0/2 10 VLAN0010 active Fa0/1, Fa0/3 20 VLAN0020 active Fa0/2, Fa0/5 1002 fddi-default act/unsup 1003 token-ring-default act/unsup 1004 fddinet-default act/unsup 1005 trnet-default act/unsup VLAN Type SAID MTU Parent RingNo BridgeNo Stp BrdgMode Trans1 Trans2 ---- ----- ---------- ----- ------ ------ -------- ---- -------- ------ ------ 1 enet 100001 1500 - - - - - 0 0 10 enet 100010 1500 - - - - - 0 0 20 enet 100020 1500 - - - - - 0 0 1002 fddi 101002 1500 - - - - - 0 0 1003 tr 101003 1500 - - - - - 0 0 After working on the switch, I had to configure the ports on the router each connected to the switch's vlan port. At first, I tried to assign IP address to the ports directly but I got this error. Router#config terminal Enter configuration commands, one per line. End with CNTL/Z. Router(config)#interface fastethernet0 Router(config-if)#ip address 192.168.1.1 255.255.255.0 % IP addresses may not be configured on L2 links. The problem was that the port which I was configuring only works with L2 layer and an IP address can't be assigned. After doing some research, I figured out that I need to first create a vlan so that I can assign an IP address to it. The created vlan with an IP address can then be assigned to a port of your choice. Here is how I did it. Router(config)#vlan 10 Router(config-vlan)#vlan 20 Router(config-vlan)#interface vlan 10 Router(config-if)#ip address 192.168.1.1 255.255.255.0 % 192.168.1.0 overlaps with Vlan1 Router(config-if)#interface vlan 1 Router(config-if)#ip address 192.168.3.1 255.255.255.0 Router(config-if)#interface vlan 10 Router(config-if)#ip address 192.168.1.1 255.255.255.0 Router(config-if)#no shut Router(config-if)#interface vlan 20 Router(config-if)# *Jan 3 09:40:49.434: %LINEPROTO-5-UPDOWN: Line protocol on Interface Vlan20, changed state to down Router(config-if)#ip address 192.168.2.1 255.255.255.0 % 192.168.2.0 overlaps with Vlan2 Router(config-if)#interface vlan 2 Router(config-if)#ip address 192.168.4.1 255.255.255.0 Router(config-if)#interface vlan 20 Router(config-if)#ip address 192.168.2.1 255.255.255.0 Router(config-if)#no shut Router(config-if)#interface fastethernet 1 Router(config-if)#switchport access vlan 10 Router(config-if)#interface fastethernet 2 Router(config-if)#switchport access vlan 20 Router(config-if)#exit Router(config)# Router(config)#do show interface (| include Vlan) ... Vlan10 is up, line protocol is up Hardware is EtherSVI, address is e4d3.f166.3fd2 (bia e4d3.f166.3fd2) Internet address is 192.168.1.1/24 MTU 1500 bytes, BW 100000 Kbit/sec, DLY 100 usec, reliability 255/255, txload 1/255, rxload 1/255 ... Vlan20 is up, line protocol is up Hardware is EtherSVI, address is e4d3.f166.3fd2 (bia e4d3.f166.3fd2) Internet address is 192.168.2.1/24 MTU 1500 bytes, BW 100000 Kbit/sec, DLY 100 usec, reliability 255/255, txload 1/255, rxload 1/255 ... Below is the routing table after configuring the router. Router>show ip route Codes: L - local, C - connected, S - static, R - RIP, M - mobile, B - BGP D - EIGRP, EX - EIGRP external, O - OSPF, IA - OSPF inter area N1 - OSPF NSSA external type 1, N2 - OSPF NSSA external type 2 E1 - OSPF external type 1, E2 - OSPF external type 2 i - IS-IS, su - IS-IS summary, L1 - IS-IS level-1, L2 - IS-IS level-2 ia - IS-IS inter area, * - candidate default, U - per-user static route o - ODR, P - periodic downloaded static route, H - NHRP, l - LISP + - replicated route, % - next hop override Gateway of last resort is not set 192.168.1.0/24 is variably subnetted, 2 subnets, 2 masks C 192.168.1.0/24 is directly connected, Vlan10 L 192.168.1.1/32 is directly connected, Vlan10 192.168.2.0/24 is variably subnetted, 2 subnets, 2 masks C 192.168.2.0/24 is directly connected, Vlan20 L 192.168.2.1/32 is directly connected, Vlan20 Now we are ready to ping the PC on the other VLAN connected by the router! Here is the result pinging from the Windows PC(192.168.1.2/24) to Raspberry Pi(192.168.2.2/24) C:\Users\Ryo>ping 192.168.2.2 Pinging 192.168.2.2 with 32 bytes of data: Reply from 192.168.2.2: bytes=32 time=1ms TTL=63 Reply from 192.168.2.2: bytes=32 time=11ms TTL=63 Reply from 192.168.2.2: bytes=32 time=1ms TTL=63 Reply from 192.168.2.2: bytes=32 time=1ms TTL=63 Ping statistics for 192.168.2.2: Packets: Sent = 4, Received = 4, Lost = 0 (0% loss), Approximate round trip times in milli-seconds: Minimum = 1ms, Maximum = 11ms, Average = 3ms Configuring the router was somewhat difficult as the commands I found online for inter VLAN routing didn't work for the router(800). I had to do some researching to find the commands that works for the router but it was fun as you don't get to do this kind of researching when you are working on packet tracer😎.