AWS ec2 putty issue

I was able to connect an EC2 instance through SSH

However, it keeps fail and timed out after i followed to step 3 of below article https://docs.aws.amazon.com/AWSEC2/latest/UserGuide/SSL-on-an-instance.html

Literally, I have just installed ssl_mod and reboot the instance, afterwards the instance cannot be accessed again by putty.

And There is no way to access the EC2 instance anymore.

Any way to solve this issue?

-----System log------

[    0.000000] Linux version 4.14.101-75.76.amzn1.x86_64 (mockbuild@gobi-build-60003) (gcc version 7.2.1 20170915 (Red Hat 7.2.1-2) (GCC)) #1 SMP Tue Feb 19 18:14:51 UTC 2019
[    0.000000] Command line: root=LABEL=/ console=tty1 console=ttyS0 selinux=0 nvme_core.io_timeout=4294967295 LANG=en_US.UTF-8 KEYTABLE=us
[    0.000000] x86/fpu: Supporting XSAVE feature 0x001: 'x87 floating point registers'
[    0.000000] x86/fpu: Supporting XSAVE feature 0x002: 'SSE registers'
[    0.000000] x86/fpu: Supporting XSAVE feature 0x004: 'AVX registers'
[    0.000000] x86/fpu: xstate_offset[2]:  576, xstate_sizes[2]:  256
[    0.000000] x86/fpu: Enabled xstate features 0x7, context size is 832 bytes, using 'standard' format.
[    0.000000] e820: BIOS-provided physical RAM map:
[    0.000000] BIOS-e820: [mem 0x0000000000000000-0x000000000009dfff] usable
[    0.000000] BIOS-e820: [mem 0x000000000009e000-0x000000000009ffff] reserved
[    0.000000] BIOS-e820: [mem 0x00000000000e0000-0x00000000000fffff] reserved
[    0.000000] BIOS-e820: [mem 0x0000000000100000-0x000000003fffffff] usable
[    0.000000] BIOS-e820: [mem 0x00000000fc000000-0x00000000ffffffff] reserved
[    0.000000] NX (Execute Disable) protection: active
[    0.000000] SMBIOS 2.7 present.
[    0.000000] DMI: Xen HVM domU, BIOS 4.2.amazon 08/24/2006
[    0.000000] Hypervisor detected: Xen HVM
[    0.000000] Xen version 4.2.
[    0.000000] Netfront and the Xen platform PCI driver have been compiled for this kernel: unplug emulated NICs.
[    0.000000] Blkfront and the Xen platform PCI driver have been compiled for this kernel: unplug emulated disks.
[    0.000000] You might have to change the root device
[    0.000000] from /dev/hd[a-d] to /dev/xvd[a-d]
[    0.000000] in your root= kernel command line option
[    0.000000] tsc: Fast TSC calibration using PIT
[    0.000000] e820: last_pfn = 0x40000 max_arch_pfn = 0x400000000
[    0.000000] x86/PAT: Configuration [0-7]: WB  WC  UC- UC  WB  WP  UC- WT  
[    0.000000] found SMP MP-table at [mem 0x000fbc50-0x000fbc5f] mapped at [ffffffffff240c50]
[    0.000000] RAMDISK: [mem 0x37087000-0x37feffff]
[    0.000000] ACPI: Early table checksum verification disabled
[    0.000000] ACPI: RSDP 0x00000000000EA020 000024 (v02 Xen   )
[    0.000000] ACPI: XSDT 0x00000000FC00E2A0 000054 (v01 Xen    HVM      00000000 HVML 00000000)
[    0.000000] ACPI: FACP 0x00000000FC00DF60 0000F4 (v04 Xen    HVM      00000000 HVML 00000000)
[    0.000000] ACPI: DSDT 0x00000000FC0021C0 00BD19 (v02 Xen    HVM      00000000 INTL 20090123)
[    0.000000] ACPI: FACS 0x00000000FC002180 000040
[    0.000000] ACPI: FACS 0x00000000FC002180 000040
[    0.000000] ACPI: APIC 0x00000000FC00E060 0000D8 (v02 Xen    HVM      00000000 HVML 00000000)
[    0.000000] ACPI: HPET 0x00000000FC00E1B0 000038 (v01 Xen    HVM      00000000 HVML 00000000)
[    0.000000] ACPI: WAET 0x00000000FC00E1F0 000028 (v01 Xen    HVM      00000000 HVML 00000000)
[    0.000000] ACPI: SSDT 0x00000000FC00E220 000031 (v02 Xen    HVM      00000000 INTL 20090123)
[    0.000000] ACPI: SSDT 0x00000000FC00E260 000031 (v02 Xen    HVM      00000000 INTL 20090123)
[    0.000000] No NUMA configuration found
[    0.000000] Faking a node at [mem 0x0000000000000000-0x000000003fffffff]
[    0.000000] NODE_DATA(0) allocated [mem 0x3ffde000-0x3fffffff]
[    0.000000] Zone ranges:
[    0.000000]   DMA      [mem 0x0000000000001000-0x0000000000ffffff]
[    0.000000]   DMA32    [mem 0x0000000001000000-0x000000003fffffff]
[    0.000000]   Normal   empty
[    0.000000] Movable zone start for each node
[    0.000000] Early memory node ranges
[    0.000000]   node   0: [mem 0x0000000000001000-0x000000000009dfff]
[    0.000000]   node   0: [mem 0x0000000000100000-0x000000003fffffff]
[    0.000000] Initmem setup node 0 [mem 0x0000000000001000-0x000000003fffffff]
[    0.000000] ACPI: PM-Timer IO Port: 0xb008
[    0.000000] IOAPIC[0]: apic_id 1, version 17, address 0xfec00000, GSI 0-47
[    0.000000] ACPI: INT_SRC_OVR (bus 0 bus_irq 0 global_irq 2 dfl dfl)
[    0.000000] ACPI: INT_SRC_OVR (bus 0 bus_irq 5 global_irq 5 low level)
[    0.000000] ACPI: INT_SRC_OVR (bus 0 bus_irq 10 global_irq 10 low level)
[    0.000000] ACPI: INT_SRC_OVR (bus 0 bus_irq 11 global_irq 11 low level)
[    0.000000] Using ACPI (MADT) for SMP configuration information
[    0.000000] ACPI: HPET id: 0x8086a201 base: 0xfed00000
[    0.000000] smpboot: Allowing 15 CPUs, 14 hotplug CPUs
[    0.000000] PM: Registered nosave memory: [mem 0x00000000-0x00000fff]
[    0.000000] PM: Registered nosave memory: [mem 0x0009e000-0x0009ffff]
[    0.000000] PM: Registered nosave memory: [mem 0x000a0000-0x000dffff]
[    0.000000] PM: Registered nosave memory: [mem 0x000e0000-0x000fffff]
[    0.000000] e820: [mem 0x40000000-0xfbffffff] available for PCI devices
[    0.000000] Booting paravirtualized kernel on Xen HVM
[    0.000000] clocksource: refined-jiffies: mask: 0xffffffff max_cycles: 0xffffffff, max_idle_ns: 7645519600211568 ns
[    0.000000] setup_percpu: NR_CPUS:8192 nr_cpumask_bits:15 nr_cpu_ids:15 nr_node_ids:1
[    0.000000] percpu: Embedded 44 pages/cpu @ffff88803e200000 s140120 r8192 d31912 u262144
[    0.000000] PV qspinlock hash table entries: 256 (order: 0, 4096 bytes)
[    0.000000] Built 1 zonelists, mobility grouping on.  Total pages: 257928
[    0.000000] Policy zone: DMA32
[    0.000000] Kernel command line: root=LABEL=/ console=tty1 console=ttyS0 selinux=0 nvme_core.io_timeout=4294967295 LANG=en_US.UTF-8 KEYTABLE=us
[    0.000000] PID hash table entries: 4096 (order: 3, 32768 bytes)
[    0.000000] Memory: 988260K/1048180K available (8204K kernel code, 1920K rwdata, 2768K rodata, 2044K init, 3876K bss, 59920K reserved, 0K cma-reserved)
[    0.000000] SLUB: HWalign=64, Order=0-3, MinObjects=0, CPUs=15, Nodes=1
[    0.000000] Kernel/User page tables isolation: enabled
[    0.000000] ftrace: allocating 25766 entries in 101 pages
[    0.004000] Hierarchical RCU implementation.
[    0.004000]  RCU restricting CPUs from NR_CPUS=8192 to nr_cpu_ids=15.
[    0.004000] RCU: Adjusting geometry for rcu_fanout_leaf=16, nr_cpu_ids=15
[    0.004000] NR_IRQS: 524544, nr_irqs: 952, preallocated irqs: 16
[    0.004000] xen:events: Using 2-level ABI
[    0.004000] xen:events: Xen HVM callback vector for event delivery is enabled
[    0.004000] Console: colour VGA+ 80x25
[    0.004000] console [tty1] enabled
[    0.004000] Cannot get hvm parameter CONSOLE_EVTCHN (18): -22!
[    0.004000] console [ttyS0] enabled
[    0.004000] clocksource: hpet: mask: 0xffffffff max_cycles: 0xffffffff, max_idle_ns: 30580167144 ns
[    0.008000] tsc: Fast TSC calibration using PIT
[    0.020004] tsc: Detected 2399.921 MHz processor
[    0.024009] Calibrating delay loop (skipped), value calculated using timer frequency.. 4800.12 BogoMIPS (lpj=9600256)
[    0.032003] pid_max: default: 32768 minimum: 301
[    0.036018] ACPI: Core revision 20170728
[    0.046999] ACPI: 3 ACPI AML tables successfully acquired and loaded
[    0.052025] Security Framework initialized
[    0.056038] Dentry cache hash table entries: 131072 (order: 8, 1048576 bytes)
[    0.060085] Inode-cache hash table entries: 65536 (order: 7, 524288 bytes)
[    0.064019] Mount-cache hash table entries: 2048 (order: 2, 16384 bytes)
[    0.072006] Mountpoint-cache hash table entries: 2048 (order: 2, 16384 bytes)
[    0.076233] mce: CPU supports 2 MCE banks
[    0.080026] Last level iTLB entries: 4KB 1024, 2MB 1024, 4MB 1024
[    0.084002] Last level dTLB entries: 4KB 1024, 2MB 1024, 4MB 1024, 1GB 4
[    0.092004] Spectre V2 : Mitigation: Full generic retpoline
[    0.096002] Spectre V2 : Spectre v2 / SpectreRSB mitigation: Filling RSB on context switch
[    0.100005] Speculative Store Bypass: Vulnerable
[    0.113770] smpboot: Max logical packages: 15
[    0.116757] x2apic: IRQ remapping doesn't support X2APIC mode
[    0.120003] Switched APIC routing to physical flat.
[    0.126535] ..TIMER: vector=0x30 apic1=0 pin1=2 apic2=0 pin2=0
[    0.174541] clocksource: xen: mask: 0xffffffffffffffff max_cycles: 0x1cd42e4dffb, max_idle_ns: 881590591483 ns
[    0.180019] installing Xen timer for CPU 0
[    0.188076] smpboot: CPU0: Intel(R) Xeon(R) CPU E5-2676 v3 @ 2.40GHz (family: 0x6, model: 0x3f, stepping: 0x2)
[    0.192033] cpu 0 spinlock event irq 53
[    0.195817] Performance Events: unsupported p6 CPU model 63 no PMU driver, software events only.
[    0.196036] Hierarchical SRCU implementation.
[    0.200295] NMI watchdog: Perf event create on CPU 0 failed with -2
[    0.204006] NMI watchdog: Perf NMI watchdog permanently disabled
[    0.208185] smp: Bringing up secondary CPUs ...
[    0.211932] smp: Brought up 1 node, 1 CPU
[    0.212008] smpboot: Total of 1 processors activated (4800.12 BogoMIPS)
[    0.216442] devtmpfs: initialized
[    0.219675] x86/mm: Memory block size: 128MB
[    0.220224] clocksource: jiffies: mask: 0xffffffff max_cycles: 0xffffffff, max_idle_ns: 7645041785100000 ns
[    0.224020] futex hash table entries: 4096 (order: 6, 262144 bytes)
[    0.228273] NET: Registered protocol family 16
[    0.232242] cpuidle: using governor ladder
[    0.236007] cpuidle: using governor menu
[    0.239387] ACPI: bus type PCI registered
[    0.240005] acpiphp: ACPI Hot Plug PCI Controller Driver version: 0.5
[    0.244347] PCI: Using configuration type 1 for base access
[    0.250764] HugeTLB registered 2.00 MiB page size, pre-allocated 0 pages
[    0.252194] ACPI: Added _OSI(Module Device)
[    0.256011] ACPI: Added _OSI(Processor Device)
[    0.260005] ACPI: Added _OSI(3.0 _SCP Extensions)
[    0.264007] ACPI: Added _OSI(Processor Aggregator Device)
[    0.271170] ACPI: Interpreter enabled
[    0.272019] ACPI: (supports S0 S4 S5)
[    0.275388] ACPI: Using IOAPIC for interrupt routing
[    0.276049] PCI: Using host bridge windows from ACPI; if necessary, use "pci=nocrs" and report a bug
[    0.280422] ACPI: Enabled 2 GPEs in block 00 to 0F
[    0.334308] ACPI: PCI Root Bridge [PCI0] (domain 0000 [bus 00-ff])
[    0.336012] acpi PNP0A03:00: _OSC: OS supports [ASPM ClockPM Segments MSI]
[    0.340012] acpi PNP0A03:00: _OSC failed (AE_NOT_FOUND); disabling ASPM
[    0.344020] acpi PNP0A03:00: fail to add MMCONFIG information, can't access extended PCI configuration space under this bridge.
[    0.349096] acpiphp: Slot [0] registered
[    0.353056] acpiphp: Slot [3] registered
[    0.356406] acpiphp: Slot [4] registered
[    0.359996] acpiphp: Slot [5] registered
[    0.360414] acpiphp: Slot [6] registered
[    0.363957] acpiphp: Slot [7] registered
[    0.364418] acpiphp: Slot [8] registered
[    0.368008] acpiphp: Slot [9] registered
[    0.371580] acpiphp: Slot [10] registered
[    0.372415] acpiphp: Slot [11] registered
[    0.375900] acpiphp: Slot [12] registered
[    0.376411] acpiphp: Slot [13] registered
[    0.380000] acpiphp: Slot [14] registered
[    0.380427] acpiphp: Slot [15] registered
[    0.384079] acpiphp: Slot [16] registered
[    0.387800] acpiphp: Slot [17] registered
[    0.388411] acpiphp: Slot [18] registered
[    0.392000] acpiphp: Slot [19] registered
[    0.392412] acpiphp: Slot [20] registered
[    0.395992] acpiphp: Slot [21] registered
[    0.396419] acpiphp: Slot [22] registered
[    0.400000] acpiphp: Slot [23] registered
[    0.400406] acpiphp: Slot [24] registered
[    0.403896] acpiphp: Slot [25] registered
[    0.404408] acpiphp: Slot [26] registered
[    0.408261] acpiphp: Slot [27] registered
[    0.411817] acpiphp: Slot [28] registered
[    0.412417] acpiphp: Slot [29] registered
[    0.416044] acpiphp: Slot [30] registered
[    0.419707] acpiphp: Slot [31] registered
[    0.420356] PCI host bridge to bus 0000:00
[    0.423606] pci_bus 0000:00: root bus resource [io  0x0000-0x0cf7 window]
[    0.424009] pci_bus 0000:00: root bus resource [io  0x0d00-0xffff window]
[    0.428008] pci_bus 0000:00: root bus resource [mem 0x000a0000-0x000bffff window]
[    0.432006] pci_bus 0000:00: root bus resource [mem 0xf0000000-0xfbffffff window]
[    0.436005] pci_bus 0000:00: root bus resource [bus 00-ff]
[    0.447197] pci 0000:00:01.1: legacy IDE quirk: reg 0x10: [io  0x01f0-0x01f7]
[    0.448006] pci 0000:00:01.1: legacy IDE quirk: reg 0x14: [io  0x03f6]
[    0.452004] pci 0000:00:01.1: legacy IDE quirk: reg 0x18: [io  0x0170-0x0177]
[    0.456004] pci 0000:00:01.1: legacy IDE quirk: reg 0x1c: [io  0x0376]
[    0.460733] * Found PM-Timer Bug on the chipset. Due to workarounds for a bug,
[    0.460733] * this clock source is slow. Consider trying other clock sources
[    0.465592] pci 0000:00:01.3: quirk: [io  0xb000-0xb03f] claimed by PIIX4 ACPI
[    0.476152] ACPI: PCI Interrupt Link [LNKA] (IRQs *5 10 11)
[    0.480222] ACPI: PCI Interrupt Link [LNKB] (IRQs 5 *10 11)
[    0.484220] ACPI: PCI Interrupt Link [LNKC] (IRQs 5 10 *11)
[    0.488237] ACPI: PCI Interrupt Link [LNKD] (IRQs *5 10 11)
[    0.511891] xen:balloon: Initialising balloon driver
[    0.520142] pci 0000:00:02.0: vgaarb: setting as boot VGA device
[    0.524000] pci 0000:00:02.0: vgaarb: VGA device added: decodes=io+mem,owns=io+mem,locks=none
[    0.524010] pci 0000:00:02.0: vgaarb: bridge control possible
[    0.528004] vgaarb: loaded
[    0.531106] EDAC MC: Ver: 3.0.0
[    0.532587] PCI: Using ACPI for IRQ routing
[    0.536465] NetLabel: Initializing
[    0.539477] NetLabel:  domain hash size = 128
[    0.540005] NetLabel:  protocols = UNLABELED CIPSOv4 CALIPSO
[    0.544024] NetLabel:  unlabeled traffic allowed by default
[    0.548042] HPET: 3 timers in total, 0 timers will be used for per-cpu timer
[    0.552017] hpet0: at MMIO 0xfed00000, IRQs 2, 8, 0
[    0.555868] hpet0: 3 comparators, 64-bit 62.500000 MHz counter
[    0.558213] clocksource: Switched to clocksource xen
[    0.568083] VFS: Disk quotas dquot_6.6.0
[    0.573690] VFS: Dquot-cache hash table entries: 512 (order 0, 4096 bytes)
[    0.581819] pnp: PnP ACPI init
[    0.586116] system 00:00: [mem 0x00000000-0x0009ffff] could not be reserved
[    0.594537] system 00:01: [io  0x08a0-0x08a3] has been reserved
[    0.601500] system 00:01: [io  0x0cc0-0x0ccf] has been reserved
[    0.608222] system 00:01: [io  0x04d0-0x04d1] has been reserved
[    0.612991] system 00:07: [io  0x10c0-0x1141] has been reserved
[    0.617641] system 00:07: [io  0xb044-0xb047] has been reserved
[    0.641810] pnp: PnP ACPI: found 8 devices
[    0.651918] clocksource: acpi_pm: mask: 0xffffff max_cycles: 0xffffff, max_idle_ns: 2085701024 ns
[    0.659212] NET: Registered protocol family 2
[    0.662987] TCP established hash table entries: 8192 (order: 4, 65536 bytes)
[    0.668084] TCP bind hash table entries: 8192 (order: 5, 131072 bytes)
[    0.672829] TCP: Hash tables configured (established 8192 bind 8192)
[    0.677593] UDP hash table entries: 512 (order: 2, 16384 bytes)
[    0.684367] UDP-Lite hash table entries: 512 (order: 2, 16384 bytes)
[    0.689599] NET: Registered protocol family 1
[    0.693893] pci 0000:00:00.0: Limiting direct PCI/PCI transfers
[    0.698659] pci 0000:00:01.0: PIIX3: Enabling Passive Release
[    0.703208] pci 0000:00:01.0: Activating ISA DMA hang workarounds
[    0.713135] pci 0000:00:02.0: Video device with shadowed ROM at [mem 0x000c0000-0x000dffff]
[    0.723220] Unpacking initramfs...
[    0.864063] random: fast init done
[    0.968913] Freeing initrd memory: 15780K
[    0.974092] audit: initializing netlink subsys (disabled)
[    0.981075] Initialise system trusted keyrings
[    0.984736] random: get_random_bytes called from key_alloc+0x209/0x430 with crng_init=1
[    0.990943] Key type blacklist registered
[    0.994506] audit: type=2000 audit(1551756108.573:1): state=initialized audit_enabled=0 res=1
[    1.000910] workingset: timestamp_bits=36 max_order=18 bucket_order=0
[    1.006273] zbud: loaded
[    1.284352] Key type asymmetric registered
[    1.287742] Asymmetric key parser 'x509' registered
[    1.291498] Block layer SCSI generic (bsg) driver version 0.4 loaded (major 253)
[    1.297323] io scheduler noop registered (default)
[    1.301463] xen:grant_table: Grant tables using version 1 layout
[    1.305870] Grant table initialized
[    1.309041] Cannot get hvm parameter CONSOLE_EVTCHN (18): -22!
[    1.313703] Serial: 8250/16550 driver, 4 ports, IRQ sharing disabled
[    1.346384] 00:06: ttyS0 at I/O 0x3f8 (irq = 4, base_baud = 115200) is a 16550A
[    1.352887] xen_netfront: Initialising Xen virtual ethernet driver
[    1.358641] i8042: PNP: PS/2 Controller [PNP0303:PS2K,PNP0f13:PS2M] at 0x60,0x64 irq 1,12
[    1.366855] serio: i8042 KBD port at 0x60,0x64 irq 1
[    1.370698] serio: i8042 AUX port at 0x60,0x64 irq 12
[    1.375506] input: AT Translated Set 2 keyboard as /devices/platform/i8042/serio0/input/input0
[    1.382858] rtc_cmos 00:02: rtc core: registered rtc_cmos as rtc0
[    1.387621] rtc_cmos 00:02: alarms up to one day, 114 bytes nvram, hpet irqs
[    1.392869] hidraw: raw HID events driver (C) Jiri Kosina
[    1.397109] NET: Registered protocol family 17
[    1.400947] sched_clock: Marking stable (1400624129, 0)->(2253558423, -852934294)
[    1.407324] registered taskstats version 1
[    1.411259] Loading compiled-in X.509 certificates
[    1.415069] zswap: loaded using pool lzo/zbud
[    1.520120] xenbus_probe_frontend: Device with no driver: device/vbd/51712
[    1.525300] rtc_cmos 00:02: setting system clock to 2019-03-05 03:21:49 UTC (1551756109)
[    1.533509] Freeing unused kernel memory: 2044K
[    1.544082] Write protecting the kernel read-only data: 14336k
[    1.548953] Freeing unused kernel memory: 2016K
[    1.554984] Freeing unused kernel memory: 1328K
[    1.575051] device-mapper: uevent: version 1.0.3
[    1.579046] device-mapper: ioctl: 4.37.0-ioctl (2017-09-20) initialised: dm-devel@redhat.com
[    1.589941] udevd[853]: starting version 173
[    1.655508] SCSI subsystem initialized
[    1.690059] Invalid max_queues (4), will use default max: 1.
[    1.720512] scsi host0: ata_piix
[    1.738747] blkfront: xvda: barrier or flush: disabled; persistent grants: disabled; indirect descriptors: enabled;
[    1.747115] scsi host1: ata_piix
[    1.750384] ata1: PATA max MWDMA2 cmd 0x1f0 ctl 0x3f6 bmdma 0xc100 irq 14
[    1.755294] ata2: PATA max MWDMA2 cmd 0x170 ctl 0x376 bmdma 0xc108 irq 15
[    1.785880]  xvda: xvda1
growroot: NOCHANGE: disk=/dev/xvda partition=1: size=16773086, it cannot be grown
[    1.992025] tsc: Refined TSC clocksource calibration: 2400.000 MHz
[    1.996677] clocksource: tsc: mask: 0xffffffffffffffff max_cycles: 0x22983777dd9, max_idle_ns: 440795300422 ns
[    2.007196] EXT4-fs (xvda1): mounted filesystem with ordered data mode. Opts: (null)
[    2.017844] dracut: Mounted root filesystem /dev/xvda1
[    2.054536] dracut: Switching root
[    2.102376] random: init: uninitialized urandom read (12 bytes read)

Couple of questions: 1. What OS are you using? I'm assuming Amazon Linux but want to confirm... 2. Did you do anything to change security groups in the Management Console? What are your security group / VPC config? 3. Are you shutting down the instance then turning it back on or did you reboot? How did you do this (either command or management console action)? 4. In the management console can you get the system log and paste here?

It is likely: 1. You configured a firewall or your security groups are not right. 2. You shut down an instance with an auto-assigned public IP. In this case the IP will change. 3. You did something that nuked a system service which is preventing the machine from booting.