有人反應捉不到ip

我第一反應是會不會dhcp ip 滿了

所以先查 log

grep -i free /var/log/messages

並沒有找到反應段有出現 no free leases

再來查捉不到ip 的pc mac

出現很多如下的 log

Nov  6 10:27:44 dhcp dhcpd[599]: DHCPDISCOVER from 9c:7b:ef:53:7f:e3 via 192.168.12.254

Nov  6 10:28:16 dhcp dhcpd[599]: DHCPDISCOVER from 9c:7b:ef:53:7f:e3 via 192.168.12.254

Nov  6 10:28:20 dhcp dhcpd[599]: DHCPDISCOVER from 9c:7b:ef:53:7f:e3 via 192.168.12.254

Nov  6 10:28:29 dhcp dhcpd[599]: DHCPDISCOVER from 9c:7b:ef:53:7f:e3 via 192.168.12.254

Nov  6 10:28:46 dhcp dhcpd[599]: DHCPDISCOVER from 9c:7b:ef:53:7f:e3 via 192.168.12.254

Nov  6 10:34:00 dhcp dhcpd[599]: DHCPDISCOVER from 9c:7b:ef:53:7f:e3 via 192.168.12.254

Nov  6 10:34:05 dhcp dhcpd[599]: DHCPDISCOVER from 9c:7b:ef:53:7f:e3 via 192.168.12.254

Nov  6 10:34:12 dhcp dhcpd[599]: DHCPDISCOVER from 9c:7b:ef:53:7f:e3 via 192.168.12.254

Nov  6 10:34:28 dhcp dhcpd[599]: DHCPDISCOVER from 9c:7b:ef:53:7f:e3 via 192.168.12.254

Nov  6 10:35:01 dhcp dhcpd[599]: DHCPDISCOVER from 9c:7b:ef:53:7f:e3 via 192.168.12.254

Nov  6 10:35:06 dhcp dhcpd[599]: DHCPDISCOVER from 9c:7b:ef:53:7f:e3 via 192.168.12.254

Nov  6 10:35:14 dhcp dhcpd[599]: DHCPDISCOVER from 9c:7b:ef:53:7f:e3 via 192.168.12.254

Nov  6 10:35:30 dhcp dhcpd[599]: DHCPDISCOVER from 9c:7b:ef:53:7f:e3 via 192.168.12.254

表示pc有送封包到 dhcp server 但 dhcp server 沒回應

正常的log應該是如下

Nov  6 13:27:40 dhcp dhcpd[619]: DHCPDISCOVER from 48:9e:bd:db:28:bd via 192.168.12.254

Nov  6 13:27:41 dhcp dhcpd[619]: DHCPOFFER on 192.168.12.221 to 48:9e:bd:db:28:bd (LAPTOP-RGQR6GL6) via 192.168.12.254

Nov  6 13:27:41 dhcp dhcpd[619]: DHCPREQUEST for 192.168.12.221 (10.0.0.3) from 48:9e:bd:db:28:bd (LAPTOP-RGQR6GL6) via 192.168.12.254

Nov  6 13:27:41 dhcp dhcpd[619]: DHCPACK on 192.168.12.221 to 48:9e:bd:db:28:bd (LAPTOP-RGQR6GL6) via 192.168.12.254

於是我把dhcp再加大範圍 加了五個ip

就正常了

所以為什麼沒出現 no free leases 的訊息

這個再查看看

almalinux 10 出來一段時間了

想說來升級一下

依照官方的步驟

https://wiki.almalinux.org/elevate/ELevating-CentOS7-to-AlmaLinux-10.html#upgrading-almalinux-9-to-almalinux-10

跑  leapp preupgrade 後

出現四個問題

Upgrade has been inhibited due to the following problems:

    1. Detected XFS filesystems incompatible with target kernel.

    2. Current x86-64 microarchitecture is unsupported in RHEL10

    3. Deprecated DHCP plugin configured

    4. Legacy network configuration found

解決方法

第4點

ifcfg-* files located in /etc/sysconfig/network-scripts/

檔案裡要加上

NM_CONTROLLED=yes

第3點

sed -i'.bak' 's/^dhcp=dhclient//g' /usr/lib/NetworkManager/conf.d/10-dhcp-dhclient.conf

第2點

rhel 10 cpu 硬体最低支援是 x86-64-v3

檢查 cpu 支援指令

/usr/lib64/ld-linux-x86-64.so.2 --help

Subdirectories of glibc-hwcaps directories, in priority order:

  x86-64-v4

  x86-64-v3 (supported, searched)

  x86-64-v2 (supported, searched)

第1點

Title: Detected XFS filesystems incompatible with target kernel.

Summary: XFS v4 format has been deprecated and it has been removed from the target k

ernel. Such filesystems cannot be mounted by target system kernel and so the upgrade

 cannot proceed successfully. Following XFS filesystems have v4 format:

    - /

    - /home

Related links:

    - Backing up an XFS file system: https://red.ht/rhel-9-xfs-backup

    - Restoring an XFS file system from backup: https://red.ht/rhel-9-xfs-restore-fr

om-backup

Remediation: [hint] Migrate XFS v4 filesystems to new XFS v5 format. For filesystems

 hosting data, perform a back up, reformat, and restore procedure. Refer to official

 documentation for details. For filesystems hosting the system a clean installation

is recommended instead.

由於這台是centos 7 升上來的 所以 xfs 是 v4

如果要再升到almalinux 10 必須要升到 xfs v5

如何檢查 xfs是 v4 還是 v5

xfs_info /path/to/mountpoint | grep crc

If the output is crc=0, it's a v4 filesystem. If it's crc=1, you have a v5 filesystem.

無法直接升級 只能備分 mkfs.xfs 再匯回資料

 rsync -avxHAX --progress /data/ /mnt/backup/data_backup/

umount /data

mkfs.xfs /dev/vda1

mount -t xfs /dev/vda1 /data

rsync -avxHAX --progress  /mnt/backup/data_backup/ /data/

最近又開始出現私設dhcp server的問題了
看了一下dhcp協定的交握
先在L3 上把udp 68擋了
注意不要下到上層的link port了
再觀察看看要不要下到L2去

ip access-list extended dhcp_deny
deny udp any any eq bootpc
permit ip any any

int ra gi 1/0/1 - 24

ip access-group dhcp_deny in

P.S.
brocade 沒辦法使用ra下acl
Orz

FWS 624升級firmware後client拿不到ip 的問題終於有了解答

目前使用的 FGS04302c.bin這個版本在打開dhcp snooping的時候
並不會在dhcp的封包加上option 82的訊息
但之後的版本會
如下圖所示

而封包向上流會經過cisco 3750
問題就來了 cisco預設會丟棄含有option 82的封包
但有指令可以讓cisco不做check

ip dhcp relay information trust-all (全域)

或

ip dhcp relay information trusted (每埠或vlan)

但目前在cisco 3750上又開啟了dhcp snooping

導致以上二個指令在這種情況是無法作用的

接下來就只剩一個解法了

在brocade的每一個port加上

no dhcp snooping relay information

讓brocade不要在封包加上option 82

問題是這個指令無法使用 int e 0/1/1 to 0/1/24 來下

要一個port 一個port下

有一千多個port 喔

想到就累 @@